Making purely cosmetic parts and testing a process.
Wrap part in carbon
Spray clear gel coat/ duratec to wet carbon and build thickness.
Problem is the gel coat won’t lay flat. I have pin holes. Everywhere.
I spray a light coat.
Then wait about 2 min.
Spray a heavier coat
Wait 2 min then a heavy coat
Any help would be appreciated.
I would suggest spraying a mist layer of duratec, wait probably ~15min until its very tacky, doesn’t stick to finger. Apply a medium coat with 10% duratec thinner. If at this point it still has the problem use a brush, Qtip or toothpick to break the surface tension in these areas. Wait ~15min until almost tacked off, spray a second medium coat, thinned ~10%. A possible 3rd coat might be needed following same procedure as above. After fully cured, sand, then final clear coat
I can see the fabric you have used is quite an open kind of weave with a fair amount of gaps in the weave and this is probably the start of the problem. You need to roll/squeegee the fabric to make sure the weave spreads a bit closes all these gaps or just more resin to be sure you fill the weave better.
Or use another carbon with a closer weave.
Duratec still does not like spraying into pinholes although can do a pretty good job if you hold the gun close and find a technique like that or brushing to fix the pinholes first.
Thanks guys.
I thought many times about doing a very li ght first coat, but my biggest worry about all that is the gelcoat setting up in the gun.
On a test piece I figured i have 12-15 minutes and by then the gun needs to be in acetone and already start to be cleaned.
I feel like a mold would of been easier to make a carbon cover for these cebter console amd dash pieces for these cars I’m working with.
Although making molds isnt my favorite thing to do. So I started to think about using a plastic vacuum forming machine to create a mold and then figure out a way to strengthen amd reinforce the flimsy plastic.
But for now I would like to figure out how to get this process of sparaying gelcoat with duractec additive to wet out and build thickness on the carbon.
Another fear is Im using an HVLP gun with a 2.0 tip and can only get a 2.5 for a bigger size. So only thinning the gelcoat 10% with duractec worries me its not going to flow well.
I guess more test pieces are next.
Thanks for the responses and advice.
When you say ‘wet-out’, are you actually wetting-out the carbon with Duratec? Or are you wetting out the carbon with resin, letting that cure, and then spraying the Duratec?
The first.
Usinf clear UV gel coat with duratec to wet out a piece wrapped in carbon…instead of wetting it out with resin or infusing or any other typical method
just mix up what you need for each coat. Theres no reason you need to mix up enough for every coat all at once. flush your gun out between coats with acetone.
I decided to try and brush the gelcoat on. It filled a few pin holes. But most of them opened back up. So i took a small artist brush and tried to fill them. They just opened back up no matter what I tried.
The surface was wiped down with wax and greese remover.
Im lost as what to do now.
Why are you trying to do it with gelcoat rather than with resin? You’re definitely making life hard for yourself…
I definitely feel like I’m making this harder than it needs to be.
I tried resin 1st. And I had pin holes and air bubbles trapped. I figured I must of been putting the resin on too thick.
I thought if I could spray something on ot would be easier and avoid those problems.
Well now I’m right back to the same problems.
Any suggestions Hanaldo?
Can I kindly ask how you would make carbon wrapped or carbon covers for a car center console?
Im doing this for a buddy and gotta fix his center console. Its for a pretty expensive car too.
I wouldnt mind making a mold for the center console piece.
Im not a composite expert…obviously. so I hate making fiberglass molds.
Anybody ever made a mold using a plastic vacuum forming machine and then reinforced the thin plasic as a mold?
Sounds like you had better pay a professional to do this job?
Everybody had to start somewhere.
This spraying gel coat technique was suggested to me on here as a relatively easy way to make a cosmetic piece wjen something is wrapped in carbon.
So I was trying it out.
I think it must be your general process is wrong. For overlay, heres a general process that I have found works well: 1. Sand your original part with 180grit. 2. If your part is not black, make it black with a black PE primer. 3. spray a topcoat like duratec on the surface, very thin coat. 4. let this come to a tack level, then drape your carbon to this surface completely. 5. wait until that resin has almost cured, then spray duratec as previously said. Try not flooding the part, this makes things worse as it traps gasses. better to let it slowly build up in thickness over several spray cycles. Use a brush to break the surface tension. After sand part flat and smooth with 180-600, and clear coat (unless it is deemed you need more top coat because too many pinholes, in which case you just repeat the process)
Spraying Duratec over a wrapped part is definitely a solid way to do it, but you don’t wet the carbon out with it. You wrap the piece in carbon, wet it out with resin and let it cure, then sand it down and spray Duratec.
When you say duratec, which duratec do you mean?
Ive been using duratec high gloss additive mixed 1:1 with clear gel coat.
Either or. Gelcoat doesn’t tend to spray nicely, it’s quite thixo so it holds orange peel. Duratec topcoat levels out better and will give you a better finish off the gun, but the way you’re doing it will work.
Try watching the Easy Composites tutorial on skinning and copying that method. Except instead of doing the three coats in a row, just spray your Duratec/gelcoat after de-nibbing/rubbing down the carbon.
Thanks Hanaldo,
Im familiar with the easy composites videos, it how I skinned a fiberglass dash.
Although it was a long process.
So I figured I’d try another technique that would hopefully prove to be less labor intensive and quicker.
Im going to continue to do test pieces using this technique and maybe even try switching to duratec top coat.
In the mean time, I am going to figure out a relatively easy way to make a mold of this part while I still have it not covered in carbon (i since ripped all the carbon off).
One strange idea that came to my head was using a plastic vacuum forming machine. I see they can be made prettt easy amd cheap. I know where a big vacuum table for a cnc router is thats not being used. So all I’d need to do is make a drame to hold some thin acrylic and find a way to heat it up. Then draw the heated plastic over the part and then hopefully have a mold I could use.
Another idea is to 3d scan it and 3d print a mold. Then use some filler primer to smooth it all up.
Any of you guys heard of people doing this with any luck?
Is the original dash made of steel or ali? If it’s plastic or composite then you will very likely find that the heat distorts the original.
In all honesty, there’s a reason the most common way to make carbon fibre parts is with fibreglass moulds - it is by far the most straightforward and economical. I can understand why you find it an unpleasant process for sure, but I honestly think you’re going to spend much more time, money and effort on trying to find a short-cut.
Thanks. An old guy I know… (my dad) said the same thing.
I reckon I’ll just do it the tried and true way of making a fiberglass mold.
And the original center console part is plastic.