Other Need Direction (Composite Tubing w/Bends)

[cmj]

I want to be clear, I have not done an acceptable amount of research prior to posting this question but I'm hoping that your experience will point me in the right direction so I don't waste a bunch of time.

I'm looking to build fiberglass charge piping for an automotive application. Here is the process I have come up with.

Solid pool noodles, insert a small diameter copper tube into the center to hold shape when bent into the final layout.

I would like to use a fiber braid/sleeve.

My questions are as follows:

The final product will see ~250*F on the hot side at most. What type of resin can withstand this temperature? As an aside, the tubing will see a positive pressure of no more than 30psi.

What is a good solvent that will dissolve the Polyethylene without bothering the hardened resin?

Should I wet out the sleeves and then pull them over the form, or form first, and then wet out? I say that looks aren't important but I am a very OCD type of person so that would be a lie. Above all though I would like it to be sturdy and functional.

I am not majorly concerned about weight, do you think that vac bagging should still be included in the process?

Any insight is greatly appreciated.

 

[Mdavies_02]

@hink320 @Nate_D

They may help you

Good luck

 

[cmj]

Thanks @Mdavies_02 !

I'm going to use this thread as a brainstorming device.. Y'all can tell me if I'm off track.

I do not think I will be able to dissolve the pool noodle BUT I believe the layup will not stick to it (or I can wrap it).. New plan of attacks is to do a thin buildup with cloth, split that down one side and hopefully pull the noodle out. Then follow that up with ~2 layers of the biaxial sleeve.

My question now is about the build up. I'm shooting for a bit better than 1/16" final thickness. My current plan is to use the 'Industry Style 7725" 8.5oz 2x2 cloth that US composites sells.. It touts the best 'drapability' which I think is important in using a cloth to cover a curving pipe. I'd like to do 2-3 layers of this material. This should leave me a part substantial enough to split and remove the noodle. I'd follow this up with 2-3 layers of the 15oz biaxial sleeving.

 

[Christian_83]

Something like this:

 

[cmj]

Something like this:

The casting tape might work for the form, then do the biaxial sleeve over top. It looks to be a very simple way to do what i'm after. I am worried about the longevity and durability of the resin used though. I wouldn't want the product to flake or unravel (especially being the inner surface of the charge piping.) This would be much easier to lay up than fiberglass cloth tho! Decisions...

 

[Nate_D]

I want to be clear, I have not done an acceptable amount of research prior to posting this question but I'm hoping that your experience will point me in the right direction so I don't waste a bunch of time.

I'm looking to build fiberglass charge piping for an automotive application. Here is the process I have come up with.

Solid pool noodles, insert a small diameter copper tube into the center to hold shape when bent into the final layout.

I would like to use a fiber braid/sleeve.

My questions are as follows:

The final product will see ~250*F on the hot side at most. What type of resin can withstand this temperature? As an aside, the tubing will see a positive pressure of no more than 30psi.

What is a good solvent that will dissolve the Polyethylene without bothering the hardened resin?

Should I wet out the sleeves and then pull them over the form, or form first, and then wet out? I say that looks aren't important but I am a very OCD type of person so that would be a lie. Above all though I would like it to be sturdy and functional.

I am not majorly concerned about weight, do you think that vac bagging should still be included in the process?

Any insight is greatly appreciated.

I wouldn't use the lost foam method for this... Your best bet would be a bladder molding with a high temp epoxy prepreg or a bladder infusion with high temp epoxy resin. Either method is going to require a clamshell mold and an oven capable of post curing to 250* F.

What is the reason for wanting to make this from fiberglass?


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[cmj]

I think I would rather use

I wouldn't use the lost foam method for this... Your best bet would be a bladder molding with a high temp epoxy prepreg or a bladder infusion with high temp epoxy resin. Either method is going to require a clamshell mold and an oven capable of post curing to 250* F.

What is the reason for wanting to make this from fiberglass?


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There is no other reasons than I've wanted to try my hand at composites and this is an interesting problem to solve.

I think I am going to try my luck with US Composites 635 epoxy resin. Use a fiber tape wound around the plug both directions, split the mold to remove the plug and then do the biaxial sleeve over top. I think this is a good simple process to learn to work with the products. The US Composites stuff states its good till 200*F.. This will definitely work on the cold side charge piping so I will start there. The project doesn't have to be a success necessarily, just an experiment that may lead to other composite creations. I'm still about 2-3 weeks out from being able to mock up the intercooler so I have plenty of time to do some more research.

 

[Nate_D]

I think I would rather use


There is no other reasons than I've wanted to try my hand at composites and this is an interesting problem to solve.

I think I am going to try my luck with US Composites 635 epoxy resin. Use a fiber tape wound around the plug both directions, split the mold to remove the plug and then do the biaxial sleeve over top. I think this is a good simple process to learn to work with the products. The US Composites stuff states its good till 200*F.. This will definitely work on the cold side charge piping so I will start there. The project doesn't have to be a success necessarily, just an experiment that may lead to other composite creations. I'm still about 2-3 weeks out from being able to mock up the intercooler so I have plenty of time to do some more research.

Cold side for sure. Hot side, maybe. Make sure the post cure schedule is followed on high temp epoxies. If you use the braided sleeve method, put your sleeve on dry and then wet it out. Might want to look into the heat shrink tubing that Soller sells. I've used it before and it works well. You will need to do a lot of post finishing work to the piece to get a good visual finish. Look into Sunshield. It's a high build polyester clear coat. Works well for getting the surface on the sleeves to a nice visual finish.


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[cmj]

Cold side for sure. Hot side, maybe. Make sure the post cure schedule is followed on high temp epoxies. If you use the braided sleeve method, put your sleeve on dry and then wet it out. Might want to look into the heat shrink tubing that Soller sells. I've used it before and it works well. You will need to do a lot of post finishing work to the piece to get a good visual finish. Look into Sunshield. It's a high build polyester clear coat. Works well for getting the surface on the sleeves to a nice visual finish.


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This is the type if info I was hoping for! Excellent @Nate_D

I will look into the heat shrink.. I originally planned on wrapping it with a wicking layer and then tightly going over it with a perferated plastic. Vacuum bagging is also not out of the question, i'm just worried about the forces on the noodle if i were to do it in the first op, or breaking/distorting the thin fiberglass core if I were to bag it second op.

 

[Nate_D]

This is the type if info I was hoping for! Excellent @Nate_D

I will look into the heat shrink.. I originally planned on wrapping it with a wicking layer and then tightly going over it with a perferated plastic. Vacuum bagging is also not out of the question, i'm just worried about the forces on the noodle if i were to do it in the first op, or breaking/distorting the thin fiberglass core if I were to bag it second op.

I wouldn't mess with bagging it. Definitely not on the first op. It will distort the noodle. First op you just want a solid shape to work off of. You could bag the second op, but if you do you will need to bag the inside of the tube as well. I've done these type of double bags before and it's not something that is particularly easy to do if you aren't very familiar with the process.

This is basically what you would be trying to do, except with wet fabric.

The braided sleeve and heat shrink will work fine and give a good surface to finish off visually.



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[cmj]

@Nate_D The image below is an exaggeration of the bends that I will need, but in your experience do you think the heat shrink will still work? Everything that i've read has been for making straight shafts.

 

[Nate_D]

@Nate_D The image below is an exaggeration of the bends that I will need, but in your experience do you think the heat shrink will still work? Everything that i've read has been for making straight shafts.

I've never tried using it with bends that extreme. It's worth a shot. If it doesn't work, then just use the braided sleeve by itself.


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