Scratch Build Project 685 Plavnik K-278 Komsomolets NATO: Mike

[HardRock]

Hardrock, ............what is that? It looks like a Japanese sub. For an instant , I thought it was a 212 ....but the sail is wrong.

Size comparison between 212 and Soryu.

[redboat219]

Reminds me of the German Type VII and US Gato. One for short patrols in Atlantic waters the other for long endurance in the Pacific.

[HardRock]

Yep, and that's probably why we will end up buying the Soryu.

[Davidh]

Hello Lads,

I would agree with Scott that we will probably end up buying Soryu. I think that this country has left the deliberation (procrastinating) a bit to late to gear up for our own production. Most people outside of Australia probably don't realise that the Collins class boats have had a real stigma in this country. Years ago they got the reputation (I think unfairly) that they were dud subs. All the negatives, hit the media but none of the positives. We had never built subs before! I suppose that's the nature of classified capability. The Collins whether you agree or not on their operational value did constitute a major nation building exercise. It brought Australian industry up to a level it had never been on.

However we face a down hill decline. what little manufacturing we had is slowly going up the creek. Holden (Australian Car manufacturer) is pulling up stumps next year, and most of our engineering is following. A Collins successor could have been a shot in the arm...

anyway.

Back to Magic Mike... No denim here. What was the point of that movie?... Resin, Cloth , Resin ,Cloth did I mention fibre glassing. Heaps of glass cloth and awkward angles around the step created by the slip at the base of the silicon mould that would sit in side the F' glass hardback being created. Fortunately a hot humid day made the resin set pretty quick. After a couple of layers of chopped strand it would be time to construct the reinforcing 'egg crating' as 'that Jorgensen bloke' describes it. Necessary if you don't want the mould to warp over time. It also means that you can get away with a little less cloth and resin. I cut out some profiles last week at school during some downtime and also got some strip pine and used these up the sides.
I have had a long tradition of using orange / red for my mould colour. Hey it works for me and these colours usually show up the detail well.

Once the reinforcing back had cured and the while shell was hard I could release it from the moulding board. This was simply done by pushing up underneath the underside of the hull and popping the whole mould off the board. Clean break and just a clean up of the yellow clay around the edges. Did have to be careful that it did not pull too much on the silicon edges.

Talking silicon, the edge profile of the silicon inside the rim of the fibreglass shell looks promising. It has flowed well into the register points and is nice and flush with the outer glass Rim.

Anyway enough for now.

David h

[HardRock]

Great work Dave.

[Davidh]

Thanks Scott,

I have been going at a furious pace. The first top hull piece popped out of the mould this afternoon. It didn't disappoint!
Hey were you flying over Terrigal at about 11,30 this morning? Thought I saw you?

Is there any chance you will be at home tomorrow. I was wondering if I could drop in and borrow those instruction manuals? I could show you the latest mike stuff.

Dave

[HardRock]

That was indeed, the dreaded Kiowa VH-TES. Alex and I went down to Wollongong for a meeting with some helicopter guys. Great trip; sharks, dolphins and stingrays in abundance. I'm in Sydney tomorrow for meetings and other mundane stuff but I can meet you on the weekend if you like. Maybe take the kids for a hop in the chopper.

[Davidh]

Hi Scott,

Thank you for the weekend offer , Saturday's a write off and Sunday is collapse afterwards. I'm sure the kids would love the offer but we'll have to re schedule it.
Thank you once again

Dave

[Davidh]

Hello all,

Back for the final large glass up. The bottom hull half. The underside of the hull has much less detail than the top and so I thought that I wouldn't need a silicon mould. This one would be done in a fashion I am very familiar with, the Glass mould with release agent, a blue PVA. Once I had popped the moulding board off and cleaned up the left over modelling clay around the side of the silicon mould inside the hard fibreglass hardback I could put down a couple of layers of PVA to ensure that the polyester resin doesn't stick to the hull. I applied this to the hull and the flange to the outer of the silicon. It's not needed on the silicon. This mould would be easier to make asking the resin to do less complex curves and the like. No silicon step to curl around.

Once done I mixed up a thickened coat of resin with talc and some orange pigment. This is simply the gel coat that will capture the detail. Once again this mould would be orange and feature hard wooden egg crating like on the top half. Increases rigidity and strength and uses less resin. As mentioned I find making these large moulds tedious, hot and tiring work but I can see light at the end of the tunnel. Once I have enough layers of resin and cloth down and can place the egg crate structure on I will be able to separate both halves, pop the master out and reveal whether the moulds are what I expect them to be.

David H

[Davidh]

Hello all,

The two halves had been laid up and given their egg crating to create a straight mould. I let them sit overnight on a warn humid evening. Then the next morning, decided it was time for the two halves to part ways. Ideally I wanted the hard shell lower hull half to separate first however both moulds started to come apart evenly. It took a little time and the prying apart of the flanges and then the inserting of strips of plastic from Ice cream buckets to help separate the master trapped within.

When I had initially poured the silicon over the top hull master I was conscious of the thickness of the silicon. Had to tell the thickness and I had to rely on incremental measurements along the length of the hull. If I knew that the height of the hull above the moulding board was 45mm then where is was measuring 55 mm above the board meant a good 10mm thickness of silicon. My concern was that there would be inconsistencies around the hull. At the very rear of the hull I needed to add a little more silicon.

The silicon mould would give much more easily when it can time to pry the two moulds apart and apart it came. As I carefully pulled apart the mould I was carefully looking for any weak spots in the mould that would need reinforcing. As I pulled the far side about a quarter of the way from the stern, stuck and was hesitant to pull from the hardback and then, A TARE!!! A small hole in the mould and a thin surface around it. I was furious and annoyed that the material had let me down. I had checked this and it seemed thick enough. Really annoyed... This stole my attention and made me really despondent even though the other 98 per cent of the mould was fantastic. The detail and accuracy of the overall mould is superb. Silicon is the way to go, minus the small annoying blemish.

I thought of the idea of doing it all over again and remoulding the entire two hull halves. I don't have the energy and or time nor the cost of more silicon and fibreglass. I have probably invested at least $100 into these two moulds. Thoughts turned to how I can then fix the little hole. I would do my best but would not be ideal. A sanding down of any parts , filler and re- etching the affected area would be the compensation.

There were a couple of extra spots where the silicon was a little thin and there were depressions in the side of the hull. Fortunately these were reasonable small and a small amount of sanding and filler would fix these. Just a bit disappointing however that I can't pop out a nice near perfect hull half. I ground out a little area of the hardback behind the silicon mould where the weak points and tare were, then I filled thickened silicon in between the fibreglass hardback and the silicon mould. Then I pressed the mast hull in as best I could and waited.

The bottom hull half is near perfect. There is almost nothing needed to be done on it.

Pulling the silicon mould off the hardback revealed reinforced silicon weak spots but some blemish still persisted , however usable and so would move ahead.

Then next step would be putting some PVA down on the lower hard shell and then a thickened gel coat. The same for the silicon, but without the PVA,

On the home stretch here, there followed the laying up of both hull moulds. A thick grey gel coat for starters then chopped strand and some weave in critical areas. T hen the moment of truth particularly with the silicon mould. Some promising looking torpedo tubes there!

David H

[Albion]

So the silicon part acts like a liner and contains the detail. From your last shot i assume that after creating a part, you put the white silicon part back into the hard model ready to create a new part?

[Davidh]

That's it Albion,

The flexible silicon mould means you capture all the detail and because you peel it off the detail is incredible , no hard moulds to break fine detail.. You also do not stress the hull if there are weak spots..

David H

[Davidh]

Hello all,

After creating the layup for the top of the mould and putting down a good amount of chopped strand and weave it was time to finally pull a hull halve. I put extra weave around the rim just to make sure that the edge when sanded back is nice, even and consistent. This pull was easy as the silicon mould would simply just ‘peel’ off the mould. It would be interesting to see how the surface detail turned out. My biggest concern was that the edge would be straight and even and that the mould would be supported with no depressions.

Eventually the part came out and although there were some blemishes and minor surface undulations the overall quality of the part is pretty good. Being my first ever large silicon mould I didn’t know how it would turn out. There were some little bits of excess resin that will have to be cut off and there are some areas where there will need to be some filler applied. The detail is fantastic and the safety line detail is excellent. These photos don’t really do it justice.

The etch lines are faithful and the overall consistency of hull diameter I am happy with. I could say it looks almost like a giant plastic piece from a kit.
Then I put the hull piece down on my large sanding board and gave the hull a good sanding down to the equator line. I also checked that the hull wasn’t warped.
The layup of the lower half then proceeded. This layup was in a hard shell mould. As mentioned earlier there is less detail on the bottom so I can get away with using a fibreglass mould for this one. The layup is otherwise just the same as with the top hull, just with a couple of layers of PVA.

Once the bottom part was pulled out, it actually came out pretty easily I could then sand it down and match it to the top hull section and see how the part lines would look and overall hull alignment. The top hull is pinching inward a little, this is not unusual as I often have this happen. The bottom hull will have an inner lip along the edge and the top hull with sit just outside of this and level and flush with the lower hull.

P.S By the way HWSNBN did you get my PM?

David h

[Davidh]

Hello all,

Everyone must be busy with Christmas stuff.

The bottom hull has come out of the mould and is really smooth. I have found that the top hull pulls in a little more than the bottom. This is OK as I will be putting a lip on the inside edge of the bottom hull that the top will sit on. Now it is over to getting out my flat sanding board and taking off the fibreglass furry bits and bring this half down to level. A good part line is essential however not always the easiest thing to get right.

Saturday morning and the little helpers were once again out helping dad with his 'sub stuff ' and then we got our annual visit from Santa in the form of a fire truck from the RFS. (Rural Fire service). Candies and lots of yellow uniforms. These guys and girls are run off their feet during bushfire season which is right about now..

Once of the things that I have had to do is go over the top hull mainly and check the detail of the safety lines hatches and access panels. In some areas around the lines there is a build up of resin where there has been a slight imperfection in the silicon mould and where there was obviously an air bubble. I have found that lifting a little blob with a knife will usually get rid of the tiny offending bit. I will have to then go over these sections with some fine wet and dry. As mentioned earlier there are some undulations that I have had to take care of with some Filler, sanding and then there will be some re-etching. This adds extra work to what I am doing however for the rest of the hull the detail in the silicon and quality of the features more than makes up for some imperfections here and there. This is a process that I will simply have to do for every hull. I don't mind.

Soon enough I had enough parts to take group photo. Of all the finished parts that is,.. in a kit. Here I laid out the parts on the only large enough white piece of plastic in the sun at probably the worst time of day. Heck it's only 38 degrees! You could almost cook and egg on the bonnet at that temp. This photo shows all the parts that will be available in the kit that will hopefully be on the market in a couple of weeks.

I finally got my lathe. oh goody!. This little cracker will be great for turning up periscopes and masts and shafts and.... I have already turned up some little brass mast stuff. I am really happy with the result..

There are some pics of the basic hull assembled and kinda looking like a submarine. From now on most of the pics are of the numerous construction steps involved in the assembly of the boat. As mentioned a couple of weeks ago I have already made an instruction manual that I have developed using mainly line drawings of the various stages of construction. This is because I didn't have any photos of the boat being built. I didn't have a single part out of a mould at that time. However now I will have photos at my disposal two, combined with the line drawings they should hopefully make all the steps clear.

Any advice would be great, don't be shy..

David H

[He Who Shall Not Be Named]

Now, that is slick! Well done, Dave. As a guide as to what to include in the instruction manual, I refer you to the technical articles at the forum, look up the BLUEBACK and Type-212 instruction manuals as a guide for you.

Merry Christmas!

M