ZX-Tex

iTrader: (15)

Yes hose jacket construction is a lot more complex than one would think. I led a project a few years ago where one aspect of it was overseeing/assisting/testing the design of some very high performance hoses for a client, performance well beyond anything commercially available. It was not easy.

I cannot go into the details on my application (sorry, proprietary information) but there are some subtle tricky aspects: How the reinforcing plies are laid up, whether the plies are woven, braided, or spiral wrapped (mandrel formed), how tight the yarns are packed together, what material the yarns are in the first place, what angle are the yarns twisted at, how the sealing material between the reinforcement is applied, curing, etc. etc. For example, with spiral wrapped, and braided hoses, one can change whether the hose gets longer, stays the same length, or gets shorter when pressurized, just by changing the angle of the wraps. Same thing with diameter.

Hoses look pretty simple on the surface but there is a lot going on with hose design, especially the high-end hoses. It is tricky stuff, and pretty interesting.

But anyway, just overdo it with the materials and you'll be fine

iWeasel410

I've done this before for a 2.25'' to 2'' 90 deg coupler before because I was in a pinch and it worked great. It's hard to make it look nice though.

SolarYellow510

Did my first test wrap today, around a 90-degree bend in a 5/8" copper soft line. Used PTFE release pretty heavy on the tube before it started. The wrap is structurally pretty weak, didn't like the way the fiberglass went on with the wrap strategy I used this time. Will have to work on that a bunch.

My "siliconizer" box to apply the silicone to the fiberglass tape worked great. I started unwrapping the end of the peel ply after about 12 hours just because I couldn't resist messing with it, and it seems to be having the intended effect on the surface finish. It is releasing from the silcone, which is also important.

This piece will basically tell me whether I can remove the hose from hard tooling once I wrap it, or whether I need to focus on soft, "lost" tooling like the florist foam. Or maybe come up with some non-adhesive inner liner, such as the self-fusing silicone tape. If it does come off, I'll put some barbs in the ends and pressurize it until it leaks.

One thing that surprised me is that the silicone stuck to wax paper, to the point the paper was giving up before the silicone. Didn't think it would do that.

Oh, and working with Permatex Super Black RTV, orange-based hand cleaner really does take it right off if it hasn't dried yet.

Duckie_uk

iTrader: (1)

Stop teasing us man!

In for pics

SolarYellow510

Sorry to disappoint. The only way I could get the wrap off the tubing was to cut it off. That stuff even stuck to the PTFE release agent! Used to use it to prevent epoxy from sticking to 20-foot aluminum tubes, but it's no match for the power of Super Black RTV.

Thinking this is best used for non-stranding failure mode parts (i.e., not cooling system). Probably still a good idea for complex intake bits where the sections are larger, making crushable lost tooling an option, and leaking is less likely to blow up your car.

Thinking about how to get a porosity-free and smooth inner layer. Most self-fusing tapes I'm aware of are activated by stretching, but will they shrink and pull away from a jacket if used on the inside? Spray-on liner?

This may be a better material, but it's off-the-hook expensive:
McMaster-Carr 8595K65
2.2-lb Kit RTV SILICONE Casting Compound
In stock at $73.13 Each

Or this as a low-buck option
6604A38
Flowable Silicone Adhesive/Sealant 10.3 oz Tube, Translucent
In stock at $27.67 Each

Thinner silicone resin would help, as well as helping wet out the cloth. Thinking about sticky-side-out electrical tape as a cheap alternative surfacing wrap rather than the peel ply. The textured surface looks good, but may be a durability issue long term.

The first experiment was a success, in that I learned quite a few things that don't work.

Duckie_uk

iTrader: (1)

Wrap peel ply over the mandrel before laying up?

georgefury1

Try some Pam!! lol

y8s

iTrader: (8)

try using mold release that's actually good:
TAP PVA Mold Release Liquid: TAP Plastics

Toddcod

iTrader: (8)

Sounds cool, I'll just buy a 90 if needed though. Or for the price of materials, I think a complete IC kit from ebay.

good Luck though. Sounds Cool.

SolarYellow510

This isn't about 90s. It's about reducing elbows in odd sizes with additional odd bends or tees that you can't even buy for $25 each getting them from England on Ebay.