Clea Gel for CF parts?

General Composites Discussions Composites Talk
#1

I’m still trying to understand the best process for making CF parts and getting the aesthetics from it also so the twill can be seen. Do you guys use a clear gel coat with an epoxy resin? I seem to remember a thread stating there was not a clear epoxy so what good would a clear gel coat do then? I’ve read about using a veil as the first layer to keep from having print-through but if veil is used doesn’t that keep from having the twill pattern in view?

I’ve read a couple different composite books but still don’t seem to completely understand. I want to have a definite understanding before I start spending money and practicing making parts. Thanks for your inputs.

#2

I am using Crystal clear Gel Coad and simply gel coat. I usually mixed together 1/2 and 1/2 for less money off course. I use this with both ways, Epoxy resign and Vinylester. The way that I spread is most of the time with paint-brush. The results it’s most of the time not so well, I must spread I think with Spray gun instead of paint-brush. But my opinion for the best aesthitic, is the mold, if the mold have very good shinning then the result is the same.

#3

you dont need to use epoxy…why this myth is going around I have no idea.

There sure is alot of people touting the use of epoxy for cosmetic parts though…

epoxy will only be necessary if youre trying to get structural strenght ie thin thin parts or something that supporst some sort of big load.

Otherwise…build your mold…polish the hell out of it and use clear gel coat and then lay up your fabric (in whatever fashion you want) and use poly resin. Its cheap and can be had in crystal clear formulas.

Poly isnt the devil that people are trying to make it out to be lately.

I take parts made in nothing but poly (gel coat is poly most of the time if not all the time) and I can stand on them without breaking or cracking.

Its all a matter of how thick you apply it and what the flexability of the part needs to be.

Save some money…dont get the epoxy…if you cant tell Im tired of the sales pitches on epoxy being better than anything else in the common applications we see them in.

#4

PS: HBracer…did you get a chance to try out the PER odor suppressor yet?

#5

No I havent…I never did get where you got it from or what it was called.

But I do have a small sample of that resin coming from your contact.

Or a derivative of it. I told him what my needs were and they are shipping me a gallon of it out.

#6

styrid

http://www.specialtyproductsco.com/Styrid.htm

#7

Thanks for the tip and another supplier for the list…:smiley:

#8

Thanks for the inputs guys. I do understand some of the differences in the matrices, but that’s a good point a body panel probably doesn’t need to made from epoxy.

#9

Thanks for the information hybridracers, one question: The poly usually have blue color, is that ok? There’s any different on the final color? Sorry maybe is a silly question.

#10

Poly can have any color from brown, yellow, blue, pink.
Don’t know the exact reasons but I think it just depends on the manufacturer and what chems they use.
Also, the exotherm can play a role in the final color also

#11

It will be a color so after you have added the catalyst, it will change color so you can know you have added the MEKP.

#12

exactly,

what I have run into is that my resin turns a brown color in the cup but let me stress this…

When I make parts I use clear gelcoat…Ive never used a resin so crappy that it tinted the dark grey of the standard carbon.

The only time I have problems is when I use bright silver texallium and I get any bridging…instead of an invisible filler I get a brown spot (at the point of bridging) and some “gold” tint to the parts.

I hate it but most of you guys wont be using any texallium as its a total bitch to work with and there isnt a gigantic market for it.

Im gonna try the styrene reduced surf resin like perfeng uses and see where that gets me. I like my infusion resin for its ease of infusing thru cheap small tubing but its more trouble than its worth on the tex stuff.

Other than that, Id pretty much slap anyone that told me I am making an inferior product for using PER resin and gel coat.

Ive still not made a single part that was in need of the extra bit of strength due from epoxy and needing to be a thin and light as possible.

Most of us are enthusiasts in the motorsports industry, we make stuff to look pretty not to have a solid tilt front end for your car that has to be pretty sound…

I dont know anyone making carbon composite lower recievers for guns…so thats out of it.

I dont work with planes…if one of my parts fails nothing is going to drop out of the sky.

And I dont care what you use…if you have cosmetic (2X2 twill) carbon that you can see all the weave in the entire part…if it gets crashed…its ruined. You cant fix it. Car hoods blow to peices, motorcycle parts get ground into dust. Who cares what it was made of, you arent going to fix it.

If you make your part right, it should flex withing reasonable expectations and not spider crack on you.

#13

A laminator friend of mine has just fulfilled a large order of motorcycle parts to a dealer in Australia, all made out of silver Eglass (texalium), and he has had no problem at all making these parts using his own custom mixed poly resin system.

Personally I think the silver Eglass looks very good on one of the newer bikes with satin black chassis, and cant understand why so few have perfected a production method for making these parts.