WTC Bulk head, End Cap material Best Used

[george]

Hello
I am Slowly putting together my parts/materials so that I can make my own WTC for my use.
My question of this group, what is the Best material to use to make the End caps, bulk heads from?
I have heard that: Alumilite,- shrinks over time, 3D printed needs extra lathe work to smooth the O ring seal to better seal, No lathe available, Auto body filler- water issue?, Epoxy poured ?

Would do the experts say?
Thanks in advance.

George

[Rick Teskey]

Save time wasted effort and money buy a pair or whole cylinder

[He Who Shall Not Be Named]

Hello
I am Slowly putting together my parts/materials so that I can make my own WTC for my use.
My question of this group, what is the Best material to use to make the End caps, bulk heads from?
I have heard that: Alumilite,- shrinks over time, 3D printed needs extra lathe work to smooth the O ring seal to better seal, No lathe available, Auto body filler- water issue?, Epoxy poured ?

Would do the experts say?
Thanks in advance.

George

Screed your own.

[redboat219]

http://www.cliffhangershideout.com/Skipjack/Skipjack-log.html

[redboat219]

https://forum.rc-sub.com/forum/builder-threads/148595-wtc-end-cap-material

[RevellU505Late]

If you are on Facebook, I suggest you join this group: https://www.facebook.com/groups/ballast.systems
Lots of good DIY WTC info. All my build info is there, including materials/tool lists with purchase links.
BTW I used HDPE stock from Amazon. Machines easily and is soft enough to take fittings without sealant. I use number drills to get the tight fit.

[george]

Already a member there. Thanks for the link.

Is there another name for HDPE ?

Canada eh might go under other name.
Thanks
George

[redboat219]

You could also try looking for Polyoxymethylene ( POM) or Delrin stock.

[trout]

There are many plastics that will work, certainly different price points. PVC was used in the Walrus end caps.

https://www.mcmaster.com/products/plastics/

Currently I am using resin 3D printed ones. I guess I would offer, do not get hooked on what to use, but more importantly just make it.

One of the pictures is from Ralph's set up for making his end caps. He is, without a doubt, resourceful and limited on his expenditures. Yet he makes some wonderful WTCs.

[wlambing]

Another, time tested, method would be to use built up layers of Lexan or other polycarbonate material. There are many drawings/designs floating in the ether on how to do this. Some skills with a sabresaw, drill and sander are required, though! One of the drawings in mind was done by Greg Sharpe, I believe, many years ago. Looked to be a quite robust unit when complete per the plan.

[redboat219]

Another, time tested, method would be to use built up layers of Lexan or other polycarbonate material. There are many drawings/designs floating in the ether on how to do this. Some skills with a sabresaw, drill and sander are required, though! One of the drawings in mind was done by Greg Sharpe, I believe, many years ago. Looked to be a quite robust unit when complete per the plan.

https

example of layered lexan sheet bulkhead

https://www.theassociationofmodelsubmariners.com/t1451-cheap-simple-r-c-sub-suitable-for-beginners-a-charlie-class?highlight=charlie

[Subculture]

You can use pretty much any sheet material to make endcaps. You only need basic handtools, but you need to be able to use them with reasonable proficiency, and like any worthwhile skill it takes a bit of time and application.

Plastic is easy to work, but can be tougher to hold a tight tolerance, more rigid plastics like acrylic (PMMA) or composites like G10 sheet are easier in that regard. I've seen endcaps made from other materials e.g. aluminium and even wood- well coated in resin to seal it. Plastics like HDPE, PP, PE etc. are best avoided unless machining them from a solid blank, as they don't take well to glues and are thus tricky to bond unless treated with a special additive. Also they tend to be rather soft and waxy in texture, which can make them tricky to finish off nicely.

Endcaps that compress the seal axially can get away with far sloppier tolerances than radial seal compression.

Some disadvantages are that you need some drawbars to pull up the endcap to the cylinder and compress the seal, and also the end of the cylinder wall needs to be thick enough for the seal to butt up against.

If you really don't trust your bench fitting skills an alternative to making them by hand is drawing out an endcap in cad and having them printed at a bureau or having some discs lasercut or cnc routed to size and then just bond them together to form a single part.

So many possibilities that were not available to modellers years ago, and they're relatively inexpensive processes capable of quality results.

[DrSchmidt]

Ist that the DeBoer Nautilus in the Background? Huge....