Scratch build Soviet Project 661 Anchar "Papa" Class SSGN K-222 1/120 Scale.

[Peter W]

David....." still a long way to go to get better " ? Mate you're building models that I would love to have and in my opinion doing it well !!

Peter

[Davidh]

Hello all,

So I have been reading over HWSNBN's write ups on spraying and finishing hulls. This will call for alot of masking tape to line around edges and so forth. I have been studying a lot of photos of Russian boats in drydock. There are some really good photos especially of Oscars with the scum line around the water line with the contrast between the faded anti foul mixed with algae dried to a powdery white colour and the dull grey sheen of the upper hull. The contrast is something.

I am assuming that these pics were taken some time after the boat was hauled out of the water. The light tan as mentioned I am assuming is the dried algae that turns to powder and is then scrubbed off. It would be interesting to see the colour of this algae immediately after the boat comes out of the water. Much more green and dark brown I imagine.



I intend to go for a look that is half way between this and just launched. It would be interesting to find out from somebody who knows, How long would it have taken for the Oscar to get this level of bleaching from a new coat of paint to this look? 1 year, 5 years? 10 years? I will have a pale orange underside where the anti-foul is fading but not completely gone.

With the top hull down I taped up the top hull to re-create the fine while line that runs around the waterline and is usually the perimeter where the scum line starts and does down the hull. This meant that I would need to create two lines of tape with newspaper once again over the top of the hull. going over the hull I checked that once again it was absolutely level and flat. This was really challenging around the booms as this line goes around the top and weaved its way around the lower stern edge of the rudder. I then gave gradual long strokes of white to get a nice consistent line.


It is important that you really press the tape into the surface otherwise bleed like what you can see at the stern can creep in. I still have to do some work on the props.


In the previous photos the top has been done with a nice very dark grey that I am happy with. Now I am turning my attention to re-creating and anti-foul red on the bottom. So I have assembled both hull halves and then start taping around the equator, making sure that the tape is absolutely level all the way around. This will require some creative taping around the stern planes and twin booms. I add newspaper over the top hull to make sure that absolutely no paint gets onto the top hull. I then fire up the compressor and mix up the oche paint that I will be using. I have a small fine spray brush that does a really good job and gives a fine consistent spray. Lots of gradual passes build up the consistency. After leaving to dry I can peel the tape off.




I though that I covered all the upper hull to avoid any unwanted spray but there is a small amount of white just to the right side of the vertical fin. You can also see the bleed around the curve of where the waterline wraps around the topside of the booms.




I have touched up the waterline. Below the waterline it probably isn't such a critical thing because the algae line will begin just beneath this line and move its way down. No I I needed to mix up and get the
algae colour right. I have gone with a tan colour. I have a lighter colour and a slightly darker one. the lighter colour will be sprayed over most of the hull from the waterline down to about halfway down the lower hull. I will then go over the area immediately below the waterline with a light spray of darker tan that will blend in with the lighter colour and will gradually lighten as it goes down the hull. I will then eventually spray an very fine hint of green right near the waterline.

[JHapprich]

Very quiet here...
The PAPA clearly shows the good quality of your kits now! Much has been improved. Really looking forward to build one myself in the future. An extraordinary boat.
Jörg

[Davidh]

Thanks Redboat.. (I still have a long way to go, to get better, but appreciate the feedback)


I'm in the final straight with this boat. Most of the work will soon go to internal fit out and arrangement. However there is still some sanding to be done over both hull halves with finer wet and dry to bring them both down to a smooth surface that will take the primer and surface coats with a nice finish. I am fortunate with the moulds for this boat that both hull halves have a really neat fit, there is only a mil or two here and there. So I spent the time looking over HWSNBN' s notes on Barbel as to how to use fuller to get a good transition between parts and create separation lines that are really fine.

So I took a file and found spots where the indexing lip could do with some sanding back so that the top hull would sit more easily over the top of the bottom. Also checking the stern and bow join to try and close the gap with how these sections will fit together more seamlessly. I've done this by adding filler over the top of the lip that slides under the top forward hull section that sets at the stern. Roughing up the lip allows the filler to stick effectively. On the underside of the top stern hull I have rubbed in Lanolin. I have also rubbed some lanolin onto the top of the forward hull section to stop any squished up filler pushing up out of the gap and resting forward of the joint, setting and creating a hard mess that needs to be cleaned off. I have also run lanolin along the side rims of the upper hull lip and roughed up the upper edge of the lower hull to take filler that will run along the edge of the hull to create a smooth transition along the length. (Got all that !)










Once you have filled the stern back joint I then used tape to hold down the rest of the hull in position and make sure that the two hulls were exactly aligned where they need to be. I also applied some tape along the edge of the top hull to make sure that the filler does not go where it ain't needed. Once done then I'd go around the join area and apply filler. Once hardened I would go around with some 180 grit and work my way down to smoother and smoother paper. The emphasis is on getting the two halves of the join to meet at the same level and have a really tight part line. On the side of the hull , the greater the difference between the hull lips the greater the amount of filler you need to lay down to get a better smooth and consistent radius. It is important that the curve leading up to the hull section that is wider, follows the profile of the hull section coming to meet it.












After a lot of sanding and reapplying of filler then sanding back I finally had hull halves that closely matched up and were looking really good. Then I gave a spray of primer around the edges of the parts and checks fit once more. The stern hull join is really close and neat and straight. Once this is done then I can look at getting the top hull sprayed with the colour I eventually want for the boat. I am going for an extremely dark grey. Virtually black but not quite. Looking at photos of the Papa this looks like the colour that has become of the boat after being in the ocean. Looking at photos of the Hulls of Papa and Alfa, the sheen on the metal does to me look slightly different to steel hulled boats. You certainly don't get rust. I cannot see any rust on this boat, being Titanium.

I have had dramas with my little spray gun and found that it was giving me hassle with the pain that I was using. I decided to use a spray can of Matt Black paint. Gave it a coat and then went over the whole top hull with the fine air brush. The top hull now has a really nice sheen. I taped around the bow at the Equator to get a nice division between where the anti-foul lower hull starts.


As can bee seen on this photo I have still yet to square the holes on the bottom hull. The brass rod sticking out of the front hull just before the join is the shaft for the front planes. I have decided to drill two brass rods to support these forward planes because they easily get banged up around the side of the pool. A second shaft also keeps the plane in the zero angle position.




















Have drilled out and filed square the vent holes that are prominent on the side of the hull aft of the fin. I like the Matt sheen for this hull.







After the top hull I will mark off the bottom hull and look at spraying a faded red anti- foul. Most likely a light orange red colour.



David H

[redboat219]

[Davidh]

Hello all,

As can be seen from the previous photos I also installed the shaft for the Rudders. A much simpler operation. However I was frustrated with the limited travel that I was getting out of the horizontal planes. As the two horizontal planes were attached to their own shaft running back and joining to a common pushrod, all I needed to do was move this common pushrod laterally (sideways) and then I would get diffing amoints of travel out of the planes. Move them far enough to one side and one would be travelling upwards and the other down. I was also getting more up movement than down. This was frustrating as I wanted consistency between both pairs. I decided to pull the individual brass pushrods off each horn and devised a new design that I have called for want of a better term a "swaybar". This is where just like the conventional way of joining the rudders around a centre shaft I have created a very long U bend. It is soldered to where the holes are located on the horns and then a single clevice is attached to a soldered horn around the middle of the swaybar. It comes close to touching the inner bottom of the hull but guarantees that the two horizontal planes move exactly with each other. I have also attached the fine brass pushrod from the tiny horn attached to the inner flap. This has since proven to be a very effective design and I get far more movement from all surfaces.






After getting all the installation right and working I then focused once more on the Vertical fins. The top of the stern hull would lower down over the vertical shaft and would have to align with the bottom hull in such as way that the rudder shaft was dead vertical longitudinally and laterally. I started by gluing the lower rudder onto the brass shaft and then making sure that It aligned with the lower rudder post. making sure that the rear edge aligned with the hole that extends up through the bottom of the hull then up through the top of the hull yet to be glued down. Once the top hull is aligned then the top rudder is slid down and glued onto the shaft and then the top rudder post is glued over the top Slotting the brass bend in the top of the rudder creating the top pivot mechanism. Once all this was done then the whole assembly was effectively glued down. The only way to majorly take it apart would be to break the join of the top rudder on the brass shaft. A large amount of surface area to do so with. I also added a small amount of bouyancy foam...




Before closing the top section down I thickened up some resin with weave and talc, then laid it down in the trough where the shafts set and the very stern section of boom. I rubbed lanolin on the shafts as I didn't want to embed them rigidly in the resin. I then closed over the top section. I checked all the connections before finally lowering the top and dealing with the top rudder. Then Glues around the equator where the two halves meet and then applied filler. I carefully smoothed over gentle radius on the fillets around the horizontal planes as the transition to roots on the hull.

A round of gradually reducing wet and dry reveals and smooth set of curves and free moving horizontal and vertical surfaces.






Like all Soviet subs Papa had a while plethora of masts. I usually put about three on any given boat. I have already spent some time creating moulds for several of them to include in the kit. It was now time to turn to the fin. Firstly I drilled a 5 mm hole in the top of the hull inside the sail profile. This would be where a hold down bolt would attach the sail to the hull. I then cut out a small piece of fibre glass and drilled a corresponding hole in it. I then glued the bolt through this pointing downwards. The fibre glass piece being glassed in place down near the base of the fin, just slightly above. The bolt passes through to hull and is met with a nut that secures it.

After this I drilled a series of fine holes in the top of the fin that sits on top of the two sides. Then getting a fine square file grinding out to a square or rectangular profile. This would be the positions of the masts. I then took the top of the sides and drilled drainage holes that would not align with the mast holes as I wanted to drill these separately as to ensure a snug fit for the mast as it slides down into both layers of glass. I then glued to top down onto the sides and fillerd around the edges to get the transition smooth. Re-scribed some detail including the faceted panels on the front of the fin similar to the array pattern found on the bow of the Foxtrot class. then prayed with a matt very very dark grey. After this, install the masts.








Getting there!

Plenty more next week. Feel free to comment and give suggestions.

David H

[Davidh]

So...

Now for all the mechanical stuff in the rear end. This boat is different in that I would be mechanising the middle flap in between the prop shaft booms. This is the only Russian Boat that I know of that has this arrangement, never repeated on Oscar or Delta. I do wish however that Papa had the twin vertical underside rudders that Oscar has, very cool. This area for this link up is really really tight. Its small and will need a very small pushrod arrangment. The one simple thing to produce will be the Vertical rudder shaft. I will not have to split it to get it around a prop.

Initially I started off by setting up the prop shafts. I glassed down an aluminium bar that would be the overall resting place for the shafts. I have thought hard about some kind of damping for the shafts and played around with some different materials such as rubber bands, seen here. I realised that they would eventually perish, along with anything rubber. Oh well see how it goes in initial testing of the shafts.
This area is so tight that once sealed up it is going to be seriously hard to access things, if a coupling or part goes pear shaped and doesnt work.







After cutting out the shafts for the Horizontal planes I needed to make a small bushing at either end to house the shafts and make sure that they aligned exactly relative to each other. These tiny bushings will simply be made out of fine brass rod and resined onto the edge of the rear hull where the shaft will penetrate. In order to do this i have to use a longer length of shaft ,coated with Lanolin to make sure that the are being resined ,which is tiny does'nt get into the bushings and glue shut the temporary aligning rod. That would not be good. I had to make a small semi circle where the bushing rests. I also had to grind out a square section for the block that sticks out of the stern plane moulding.





I spent a fair bit of time making sure that the top half of the stern also aligned up and that there was also a semi circle where the bushing would be pushing into the top half. I had to carefully measure the distance between the shaft and both stern booms to check for square. This took quite a while but is absolutely essential. Forward of the shaft is the aluminium plate that will be the mounting for the twin shafts that will be installed a little later.

After this I carefully ground down the excess glass around the edges of the bushings to allow the top hull stern section to simply push down over the top and close flush. The two holes were where I didn't quite get the alignment right the first time for the vertical rudder shaft. Anyway after this I needed to start installing the shafts because I needed to check that there would be enough space in between the outer side of the boom and the prop shaft in order to get a swinging push rod horn in for the horizontal plane.

I have the brass rods extrude about 5-6 mm from the bushing, thus giving just enough room for the brass plate to be soldered to the shaft allowing a push rod to be attached. As it is there is about 4-5 mm clearance between the side of the hull and then side of the shaft. Just enough to get a horn and clevice in place.







The prop shafts are held in place by a aluminium plate that is flexible and can be bent around the shape of the two shafts. I have also places a silicon nitro line "sleeve' over the shafts where they will clamp down over the aluminium bar that is glassed down. This arrangement will probably be changed as ultimately the alignment of the shafts to the outlets on the WTC are more important. These won't necessarily sit nice and neat on the aluminium as I have them here. I also intend on Gluing or glassing at the tapered rear end so that the shafts don't jump around which they'd likely do if not properly secured. I know this back end looks messy, however when the top is glued down, you ain't going to see it..



























Until next time...

[Davidh]

Hello all,

I found a whole heap of photos showing the lip that I used for the stern of the hull and the front that I did'nt put up last week. Because the rear top of the hull is essentially a double curve I cut out a rounded strrip in two to effectively cover the curves. Roughing up the surface and then using some P'yester resin mixed with some chopped strand gives good adhesion.

[Davidh]

Hello All,

After getting the top and bottom level and straight, I turned to dealing with the registration lip that would run around the inside of the lower hull and hold the top down. This is made from a strip of fibreglass that
is glued along the inside of the lower hull with the upper edge of the strip protrude about 3-4 mm above the edge of the lower hull. Once glued down I ran a file along the rim of the lower hull to smooth down any blobs of resin that may stop the upper hull from completely closing.

I once again used my customary bow assembly technique of gluing the lower hull at the bow to the top bow and using a small aluminium flat bar with a screw thread in it to secure the top and bottom hull sections and a lip in the rear of the upper hull to slide in under the back top hull section attached to the lower hull. This flat bar has to be glued onto the bottom bow section before the top and bottom can be glued together.
The bar points stern ward and aligns up with a hole drilled in the bottom of the lower hull that comprises the rest of the hull. I marked out a line, that runs from one side to the other, this will be where the lower cut will be made. I then glue the plate across the line. The will be cut out from underneath. I wrap the end with the solitary hole in sticky tape in order to make sure that the fibreglass does not stick to this end. Then I drill extra holes in the other end to allow the resin to flow all through the holes securing further, the front end.

Once this is done and glued securely , I then drilled the rearward hole with a smaller diameter hole that will act as a pilot later on for a larger one. Marking where the lower cut would line up with the top hull I then roughed up around the bow rim on top and bottom. I then secured down the top and bottom hull in just the right spot with tape and then glued the top and bottom section around the bow. I laid a thin strip of cloth and resin around the bow and let that set.


















I would not glue the stern top section on till I get all the stern arrangements just right. This would involve aligning and setting the two stern shafts in place and making sure that the horizontal planes were installed aligned and with free movement. This would involve a fair bit of time and fine tuning to get right. I initially started with an aluminium bar that would be the support for both the shafts. I have made a thinner aluminium bracket that bolts down over the top with a single bolt in the middle. The shafts are dampened by having nitro silicon line sleeved over them to dampen vibration. More detail to follow next week.

David h

[Davidh]

Hello all,

After a busy week in which I went bush then found out by Friday that we have a new Prime minister. Hardly know anything about this new Bloke, Scott Morrison.

Anyway,.....

Working through the finer points of getting the hulls nice and even and filling and sanding the odd undulation. I then found myself at a point where I could look at the fitting of the stern appendages and how they would go together. A couple of weeks earlier I has cast the stern horizontal planes and then vertical top and bottom rudder sections. I had yet to create a mould for the inner flap ( the horizontal stern plane that sits between the booms.) I have cast a couple of rounds and they work out quite well. It was simply a case of fine sanding and the usual adjustment to get them all working the way they should.





A part of this involved cutting out and filing the square holes that allow the support for the urethane stock to fit inside the edge of the hull and allow a little more support for the appendage to grip onto the hull where required. I also had to drill and sand the hole for the rotating shaft of the movable surface. I then had to spend a considerable amount of time ensuring alignment and that the bras rods and absolutely aligned and horizontal ,or vertical for the rudders.

In the case of the vertical rudders, the holes marked for the shaft needed to align dead vertically for the top and bottom and at the same time having the hull top and bottom align and sit perfectly atop one another. After drilling the holes in the registered positions I then moved the top hull over the bottom and lowered a brass shaft through both hole. Then carefully slide the top hull incrementally around over the bottom hull and watching how the brass rod gyrates. (Not much, a degree here or there.)













Once I had this alignment done to my satisfaction I then started using a round file to remove the material in the twin booms where the twin brass prop shafts would be laid.
I then needed to carefully remove a little more material to make sure that the shafts sit level and true with the edge of the lower hull.


David

[Davidh]

Hello all,

So I spent some time cleaning out the hull mould and washing off the PVA residue. Then I sprayed in a couple of layers of PVA onto the bottom hull. I l also washed out the top hull silicon mould and dried it, ready for a couple of very fine spray coats of PVA on the silicon. Once this was done and dry I mixed up a batch of gelcoat and moxed some grey pigment into it. Gelcoat is great because it'sn not too thick to not fill crevices but thick enough to generally cling to sides and hold with a nice consistent thickness.

Drying to a tacky consistency then allowed me to lay up the first layer of Glass. I try and use the 6 oz cloth as its light and will generally work its way around gentle corners well. Allow that layer to harden then allows me to go over the surface and sand back any tiny or large bumps and spikes where a bit of glass weave for some reason may be sticking up. This will cause a nightmare for laying down the next layer and getting a really big air pocket underneath. After checking the surface and making sure its smooth I wet up the surface and then put on a thicker chopped strand layer. This roving layer is quite thick so you need to really wet it up good. As you work your way around the rim I sometimes find that the material will work its way down the sides, so sometimes I will add strips of finer weave around the rim just the thicken it up enough so that when I sand it later I can get a really neat and consistent edge.

I do this with both hulls the silicon mould and the hardback. After a couple of days these two hull halves are ready to pull.






















Finally the moment of truth. Pulling the hull halves out of the moulds. A couple of weeks of work and the first hull parts have finally been made. The silicon mold by nature just peels away beautifully, revelaing superb detail. There was some slight undulations but overall straight and true. I am convinced that the embedded mesh plays a part in this. The sides are straight and the top deck of the mould is also true. Of this I'm really happy. There is also no air pockets nor tiny balls of resin where the resin has found a air bubble pocket in the silicon. None whatsoever! The surface is also very consistent. I had been having a problem a couple of months ago where there was surface crazing on the resin where it must have separated from the silicon or there was some kind of movement just before hardening that was driving me up the wall.

The lower hull took a little more convincing. This is because I'm pulling it from a rigid hardback. I usually start at the back end as there is less material to have to dig under. I usually cut plastic strips made from
cut strips of plastic 2 litre muilk bottles. Push them under the rear and push and push until it comes up the other side. Pull back and forth as you work your way along the hull until you feel the rest of the hull forward of where you are start pulling away and before you know it, it has popped out.

I am really happy with how these two parts have come out. I then take my dremel tool and cut away the excess mess that sticks out above the rim generally bring down the surface to roughly flat and definitely less sharp and rough.





As you can see the surface detail is reasonable. Subtle undulations, and some rough patches the bane of my modelling existence are evident and I has some areas where the gel coat had let me down somewhat. I thought it was thick enough. Once roughly cut out with the Dremel it is a date with the big broad and long sanding board that will bring the equator down to nice and straight. This last photo shows the alignment of the stern top and bottom sections with the twin booms evident. These two hull parts are very close and will make the set up and fitting out of all the control surfaces a lot easier...

Then almost all the hull work is fine filling and sanding....

Stay tuned......


David H

[Davidh]

Hello,


After spending a couple of days laying up several layers of glass roving and being over it. It was time to build the plywood frame for the bottom hull mould. Once again I cut the frames so that
they would match with the overall shape of the layout. A curve at the bottom that would fit along the width of the hull and be flat at the top to meet the sides. The egg crates are really good as they
double up as a really sturdy support when you are laying up a hull mould.

Once this was done it was the usual waiting till all the layers had fully dried and then working out how to pry the two halves apart. This would also be the point at which you saw whether almost two weeks worth of work has been worthwhile or If you will end up frustrated that something early on ruined or nearly ruined the surfaces in both the Silicon and hard shell bottom mould. Fingers crossed.






As you can see from the pics, the rim (flange) on the bottom half is narrower then the top half. this is primarily due to the extra width needed to accomodate the
silicon mould of the top half mould. Having the purple masking off tape would certainly make separation of the two halves alot easier.

Once this was all ready I one again got a spatula of sorts and carefully found the separation between the two halves. Prying the blade along and being careful that it was not catching on an
uneven section of glass and riding upward and away from the separation plane was important. Once I made a separation all the way around I could them work my way in with a soft plastic "chisel' of sorts something that could be used for prying but would not scratch the surface. Sometimes I find it hard to predict which mould will separate the most easily , leaving the master in the other mould. After some vigorous moving and prying the top half ended up separating the most easily. I spent a bit of time inspecting the top surface. The Silicon had done and incredible job. The Surface detail was brilliant and there were virtually no air bubbles that can be caused at the beginning if you put too thick a layer of initial silicon down. (I don't have a Vacuum chamber and pump yet) to evacuate all the air before pasteing up the silicon on my moulds so I have to put down a thin layer for starters. It worked! The Sides are nice and straight, I believe the result of embedding a rigid "L'" shape of rigid wire mesh into the silicon. I alos did the same along the top of the mould so the silicon is dead straight along the upper surface of the hull. I also don not have any weak points in the silicon. This is something that had been a problem on earlier moulds. This mould is solid. It is really thick and I love it.





That left the bottom mould holding onto the master. This would require more prying and some frustration. However after a little while the master pulled from the mould. This is where sectional glued master front and back ends can come back to bite. As I was prying out the back end it started giving way but the front section stayed and the hull parted along one of the sections joins just before the PVC pipe breaking that Papa master in two! Oops.... Nice clean break at least!






Clean out the Residual PVA , peel off the tape and sand back the flange, spray a couple of layers of PVA back on and star the first layup!

Enough for now,

David H

[Davidh]

Hello all,

So after spending a couple of days laying down layer after layer of fiber glass and waiting for it to dry I made sure that the lower most layer is thick enough. The next step would be the splitting of this top mould off the the particle board splitter board that separates the two halves. The plywood box frame had also hardened during this time and is now quite rigid around the top.

After a couple of hours I picked at various parts of the mouild to check that it had dried and hardened all over and then started the process of separating the wooden splitter board from the top half, pulling out the master and making sure that the master did not move inside the top half of the mould. You don't want the master remaining with the wooden board and the pulling away from the top silicon mould. This would not be good.

Fiber glass does not stick to the veneer surface found on particle board, so I have never used a release agent with it. Taking a knife and spatula I started running the blade around the outside rim of the fibreglass outer layer. If the glass has hardened up properly , it will start separating in front of the blade as you move along, the change in angle of the material moving up above the blade causing this separation pattern to occur and a colour change as the glass moves away from the backing. Initially I worked my way around the rim, not progressing too far in, gradually working further in deeper and then up against the edge of the silicon mould itself. You need to be careful that the blade doesnt hit any irregularities that might cause a split in the material and delamination happening between layers of resin and glass that make up the flange.

Looking under the separated flange I would look to see that the silicon mould was also coming up with it. Prying the siliocn mould away in some places where it was tending to stick to the board required more gentle persuasion. Turning the board over so that the top of the upper mould is resting on the bench I would them push the bottom of the master into the top mould whilst pulling the splitter board away. Boreis separation took a bit of work however Papa's came away quite easily.

Once this was achieved I had a look around the flange and where the silicon meets up with the outer flange of Glass. There were some undulations and areas where the original gelcoat had'nt set quite properly. This initially really annoyed me. Leaving it for some time in the sun slowly kicked the curing process along a bit further. I then took a screw driver and spatula and scraped away the residual clay that was originally pressed around the edge to create a seal between the master and the board. Then coats of PVA.


Several coats of PVA release agent later, I also decided to run some tape around the joint between the silicon mould and the hardback. This will also make sure that no resin from the bottom mould will seep in between the silicon and hardback of the top mould. It is a bit dissapointing that I had to do this. All my other molds have been so tight I have not needed to do this before. Should probably help with part separation between the two halves. The top and bottom will never need to mate and be tight when producing a hull mould, a precisely flat surface in the flange is not absolutely necessary. Its the rim of silicon that needs to be dead flat as this will be the edge of the top hull half. I did a few more layers of PVA over the flange and the master. Once this was done I could lay up the first Gel coat of the bottom mould hardback. Then once again repeat the process, just without silicon..







Yay! I found a reliable way of getting bigger pictures!

Enough for now.


David H

[trout]

I have a comment....wow. I appreciate David that you take the time to share your progress.
We are getting 45 - 46C (113 - 115F) degree temps this past week and today. Here in Las Vegas, NV we have 2 - 3 months when it is really hot and one of those months when it feels like a few degrees shy of the sun.

[Davidh]

Thanks Scott and David,


Onward. After having all the silicon cured and the perimeter barriers removed, I laid down a gelcoat of Polyester resin. I mixed up a thick batch and added my customary orange pigment. (All my hulls have an orange hardback after the silicon.) Once this was laid down I have it a fair amount of time to cure. I had to put down a reasonably thick layer in order for it to get into all the crevices and so forth as the last layer of silicon was given a thixo mix to thicken it up and make it really rough so that the hardback would register and be rigidly in place when needed.

Now I get on the long road of fiberglass build up. A couple of weeks ago I bought a 4 litre tin of resin. This has saved me a lot of time and effort getting top up litre tins from the local hardware store (Bunnings) which can be a bit overpriced. Soo much better getting it from a wholesaler, even if he is a 40 minute drive away. I started of by using heads of chopped strand. This stuff is thick and because it doesnt need to be detailed ideal for this application where you just want thickness and strength. So layer upon layer over the next couple of days and wanting the temperature to get up to at least 20 degrees. that would be nice.
The step where the silicon sits against the side of the hull and met the perimetre would need the fibreglass to curve around a radius. This is something Fibreglass never likes doing. I have a huge bail of fiberglass strange, long strings of the stuff and so I simply cut up several lengths and wrapped it around the base next to the step to build up the level before laying down chopped weave up the side where it doesn't need to conform to such tight bends and curve.

I heard on the radio in the workshop how Britain may get up to 37 degrees today and that would be their hottest day on record. What,! we get over 40 degrees a couple of times in December and January. Anyway after a couple of days and lots of layers later It would be time to work out the egg crating. As David shows in all his builds and I have adopted out of common sense is the egg crating that stops a mould , no matter how solid it may be, from warping. I had this unfortunate experience years ago when I did some wing moulds for one of my gliders and it warped really badly. This box would simply be made of 3 ply sheet that was cut down to about 120mm wide and a box would be created out of it.






The plywood sides need to be high enough to be above the level of the mould. There would be three supports.
One at the front, one in the middle and one at the back. These needed to be cut to the approximate profile of the fibreglass layup at that point. Once glued up I layered a couple of extra layers of glass around and inside of the box just to make sure that it had a rigid connection to the base of the mould all over. It is crucial that the egg crate box is firmly holding down the main section of the mould. Its job is to resist warping however it also acts as a really good stand...

Any comments or suggestions appreciated..

Enough for now...

David H