Door pillars

General Composites Discussions Composites Talk
#1

Evan - Great write ups! I have been trying to learn about carbon fiber fabrication for nearly a year now, off and on.

I have even tried - trial/error attempts. After running across this help forum, I’m relieved! I’ve read numerous articles regarding and emailed companies who do fabrication of aftermarket parts as you do, but sometimes I feel that I’m prying into their business when I ask specific questions regarding materials they use.

I’m assuming this is what this thread is about - questions questions questions! :smiley: :smiley:

1st project -

This project I have been trying to work with for quite awhile and have had no succcess whatsoever - maybe you can review my basic process and see if you agree, I would highly appreciate it.

Objective: Carbon Fiber Door/Window Pillars …Esentially covering stock (verticle) door/window pillars w/ CF and having a deep / crystal clear / 3d finish.

These pillars are unforunately not flat - they have an arch to them to fit the body lines of the car. Hence - not the ideal surface in my learning. I have attempted many ways to manipulate the drapping of the CF upon the pillar. Unfortunately, it seems that it continues to bubble up / float around the edges of the material.

I have followed essentially what your basic tutorial w/ these parts but w/out success - my biggest concern is that I feel that I’m not using the correct type of resin and preventing bubbling / floating of fabric.

Resin: I’m trying to find a resin that works ideally with CF that gives those characteristics stated above (deep / crystal clear / 3d finish). I’ve tried multiple resins but unfortunately - not many people here in this town are knowledgable w/ this fabric.

:?: What resin is best used to obtain such a finish?

:?: Process correct?
:arrow: By following your basic tutorial - cutting the fabric larger than the item to be covered - saturate both fabric and surface part (waiting x minutes for tackiness of surface)… allow fabric to drap evenly / naturally - assist with any uneveness / bubbles - allow to cure - cut edges w/ cutting instrument and then sand to edges w/ appropriate grits. Apply further coating if needed in between sets / clear coat w/ UV protectant for exterior use.

I suppose I’ll leave this reply as it is before picking your brain / talent / skills many more rounds w/ my questions that I have from covering a dash / vacuum bagging / molds / etc :shock:

Thank you so very much for your time :slight_smile:

  • Jason
#2

Hey Jason,

Welcome to the forum. Are you referring to the exterior pillars or are they the a/b/c pillar covers inside the car?

Are you getting bubbles only around the edges? Are you wrapping the fabric around the edges or do you let it hang free? Have you tried waiting longer for the epoxy to get tackier on the surface? You can also try wetting the surface only and place the dry fabric over it once it’s tacky. Once the epoxy is harden enough to keep it in place you can start wetting the fabric from the top. That’s all I can think of for now. Let me know exactly which pillar you’re working on so I can have a better idea.

Thanks,
Evan

#3

Ooops. Forgot the resin. Epoxy resin is ideal for composite work in general. Less dangerous and doesn’t smell either. You just have to make sure that the epoxy does not yellow out from reading the label or asking the manufacturer. You usually can’t go wrong with West System or even US Composites. None of these resins are UV protected so you’ll have to do that with clear coats.

Some resins that do have built in UV protection are certain types of polyester resin. Stay away from the boating grade polyester resins because they do not cure clear but rather purple-ish. You’ll want to find something that’s called surfboard resin. That stuff cures water clear and can be wet sanded and polished without using a clear coat.

The thing with using polyester is you’ll have to get 2 different mixes. A laminating mix is sticky and not sandable. Use that to laminate and build up your layers. For the top layer, you’ll have to use the surfacing mix with has a was agent that allows you to sand it down. This stuff smells bad and could blind you so use it with care.

And then there’s vinyl ester resin too but I don’t see the appropriate use for it in your case.

Evan

#4

Hey Evan -

Thank you for replying to my questions! It’s great to have this forum! Let me answer the questions you had listed.

:?: Are you referring to the exterior pillars or are they the a/b/c pillar covers inside the car?
:arrow: Exterior pillar - along side the window (vertical sash see picture below). But I’ would sure like to learn how to do the interior ‘A’ pillars etc :smiley:

:arrow: Part #3/6

:?: Are you getting bubbles only around the edges?
:arrow: Yes - it always seems it would bubble or float the fabric up at the edges when it would cure.

:?: Are you wrapping the fabric around the edges or do you let it hang free?
:arrow: I have tried both.

:?: Have you tried waiting longer for the epoxy to get tackier on the surface?
:arrow: I have tried waiting, but I may have to wait longer 30-45 minutes as you proposed in your write up.

:idea: You can also try wetting the surface only and place the dry fabric over it once it’s tacky. Once the epoxy is harden enough to keep it in place you can start wetting the fabric from the top.
:arrow: I’ll have to try that idea - thanks!

Thanks again for the reply and I appreciate all the time involved in answering my questions.

  • Jason
#5

Awsome! I’ll look into finding those manufactures here locally!

Thanks again!

  • Jason
#6

Jason,

If you’re going to try doing it again with epoxy resin, just wait longer until it’s really tacky and place the dry fabric over it like I have mentioned. If you find a polyester resin that you want to try, do the same thing except you can just wait until the first coat fully cures. The laminating mixture of the poly resin is tacky when cured so you’ll be fine. Be sure to use the top coat before you sand because you won’t be able to sand down the laminating mixture. If you need a thicker top coat, wet sand it a little bit before adding another layer. That will remove the wax and allows the next layer to bond properly.

Polyester sounds like a better way to go but it’s not. You should stick with epoxy if you can.

#7

Hey Evan!

Last night and today I have been working with my door pillars again. I went to the local hardware store and picked up some EverCoat Epoxy Resin. It was a 1:1 w/ hardener. So far, it’s turning out great!!! All this time, this resin has sat before me probably saying buy me buy me don’t waste your money on that junk!..

:arrow: Process:

  • I sanded the door pillar down w/ 80grit and washed it off.

  • Brushed down a layer of resin - waited 15 minutes - it starts tackin up around 30mins - layed down my CF fabric w/ about 1 - 1 1/2 inch CF border.

  • Evened it out by hand - cut diagnol cuts in the corner of the fabric so the edges could bend freely w/out bringing up the other edges - waited about 5mins - brushed on a small layer of resin ontop of the fabric - once adequate amount - lightly exhaled on the resin to help release air bubbles in the resin (co2).

  • Let it lay up over night.

  • Next morning, cut down the surrounding fabric w/ a razor - cut my finger - took dremel w/ a cylinder 80ish grit sand bit - sanded down all the edges flush to the plastic - washed it up.

  • Took 200 i think or 400 grit and wet sanded it down (surface / edges) - washed it up.

  • Brushed on a thiner coat of resin - currently letting it lay up over night - will come in tomorrow - wet sand it again - bring down the edges if needed - and clear it !

Thanks for all the help, I’ll take pictures of the before and after once I get em finished up!

  • Jason