stangkilla1

I need to know how to polish the final coat of resin. Here's what happened.

I brushed on 2 coats of resin with a small amount of hardener, but it was taking too long to dry (seemed like it was'nt drying at all) it was looking perfect with the first two coats. The gloss was deep and it was shining but...... I decided to add one more coat with a lil more hardner in it and it dried sure enough, but with a hazy cloud on top.

1) Should I have waited for the first two coats to dry eventually?

2) Did I add too much hardner?

3) What kind of product do I use to polish it to a shine?

4) or should i just go to autozone and get some sray laquer?

I got the general idea (after messin up 4 yards lol) but I'm stuck on this problem. Lownslocamaro, the pieces I messed up were two of yours (yes I was gonna make yours before mine lol), but practice makes perfect so yours are still in the making. BTW I also finally understand fiberglass now, it's easier than carbon lol.

lownslocamaro

I'm confused, you can't really polish resin, at least I've never tried. Did you make a mold for this? Do you have a female mold for your male parts? Generally, you can polish the clear gelcoat that is on top of the resin when you pull your part. For example, you have your mold, its waxed and sealed, apply gel coat, apply carbon and resin, let cure, remove part from mold. Polish clear gel coat and you have shiny looking carbon fiber. Basically what I'm saying is in every molding situation, you have a smooth side from what you molded off of, and a rough side, the back of the part. Is the rough side the front of your part? If it is, its not good but all hope is not lost.


Also, two important tips on dealing with the resin, don't guess on how much hardner to put in. Are you using polyester resin catylized with MEKP? Get out a scale and measure by weight. 2% is the norm but you can generally mix anywhere between 1 and 5% safely. I always mix at 1.5% and am simply pacient. 20cc per quart is about right as well. Lastly, resin satuaration of carbon or any composite is important. You want the least amount of resin possible to fully saturate your cloth/weave. No puddles.

If its rough you can topcoat your part with any sort of urethane clear to get that deep look. Don't use a spray can, get some clear from the auto paint store, You could pour it on and let it roll off the edges, It will take some time to get really hard, but they have been doing bars and tables this way for a long time. If possible, spray it, thats the best. Also, don't apply any topcoat for a little while, stick your parts out in the sun. Resin does have some shrinkage issues and the longer you let it cure out and get hot, the more complete the cure.

I need more info to fully help you with your problems, like how you molded these parts.

stangkilla1

I used the OEM parts, foiled them, waxed, laid the carbon and then applid a thin first coat of resin. I let that dry for an hour (but it was still too wet), applied a second coat with a few more drops of hardner, and after this coat it was looking perfect, I mean really perfect!!

But it still was'nt drying as fast as my test piece had( and I doubted if it was drying/curing at all) so..... I added a third coat with even more hardner in it and that was my biggest mistake. It dried, but with a very ugly dull yellow haze to it. So it worked and it did'nt work lol! Would the first two coats have dried under the sun? or in an Oven real quick? I'll be right back (gotta go pick up my girl) and I'll post some pics of what happened and how it looked with the first two coats.

stangkilla1

Oh yea I did use polyester resin with MEKP

lownslocamaro

Alright, on the good notes, its good to see you used foil and wax to release your parts from the originals. As far as your resin cure issues, make sure you are using fresh MEKP, and by all means, don't guess how much to put in. I have this really cool MEKP dispenser that does all the work for me, get one. It is a squeeze bottle with a shot glass on top, you squeeze the bottom and it fills up the shot glass to cc's. No need to resin coat your foil and let it cure before applying carbon, do it in one swift shot. Just wet your foil down with resin, lay some carbon on, and let cure. If you want a thicker part, lay some glass down first and top coat it with carbon. You should be making your parts slightly oversized so you can trim them to fit so the edges are nice. If you want that super smooth, thick shiny look to your carbon pieces, you need to appy a urethane clear on top of what you have. You should not have puddles of resin on your part that you can polish. Your parts should look "wetted out" but not soaked. After it cures, you can release your parts. Your outside surface might feel tacky, but resin doesn't cure tack free. Scuff the surface lightly with a red scuff pad, and lay down the clear, and more, and more, and more. This is the only way to build up enough material so you can sand and polish it perfectly smooth. Use a high quality Urethane catylized clear. I reccommend Valspar, Dupont, or Upol. Also, let your parts really cure out before you put any clear on em, like, let them sit in the sun for a few days, it would be better to leave them on your mold so they don't warp in the sun. Theres more, just can't think of it at the moment.

Patrick

stangkilla1

Oh OK lol!!!

A few days, I was thinking a few hours. Thats what I get for being impatient. So if I would have left it at the two coats, then let it dry it would have come out perfect. Only problem I seem to have now is that I cut too close to the eges before laying the resin which left me with splinters that I have to sand down. I would have rather sanded down non-splintered CF because it splinters over the OEM part a lil bit. But I'm getting there lol.

The parts that I was making for you were the rear panels (right and left) but dont worry I'm waiting on another batch of carbon and this time you will like the results. I guess I thought that I would learn carbon and have it mastered as I do everything else (show me once and I know it forever) but carbon is tempermental and requires patience, so I've learned my lesson. No more speeding through it.

stangkilla1

Here's the link, I also started fiberglassing my amp rack.

http://camaroz28.cardomain.com/memberpage/239349/8

lownslocamaro

Ok, way to much resin. You want to keep the amount of resin down to a minimum, you will create that ultra thick looking depth with clear urethane. If you use too much resin, your parts will tend to distort over time.

Your amp rack looks good, I would smooth the foil down a bit with a bondo spreader, I use spray adhesive to hold the foil down. I reccommend Partall Paste No.4(I think 4) for your release agent, you should wax the foil and then start laying glass.

stangkilla1

yea I was wondering how to smooth out the foil. BTW where do you buy that super 77 stuff? I tried a few places with no luck.

I'm going to make two molds of the amp rack, one for the car and one to make carbon fiber molds with. I really like working with the fiberglass (it's kinda fun) and it's easier than laying the carbon but... I'm not a lazy person so "easier" just means I need to perfect my CF skils. How's your C5 panel coming along? I read all the posts asking if you were going to sell them, I understand if you dont mass produce them. I realize the time constraints in working with glass and carbon. I'm doing my work when i can get any free minute.

When the next batch of carbon comes in I'll be using a real Epoxy resin, super 77, let it dry thoroughly, and DONT RUSH IT!!! That was my mistake, I was sooo ready to see the final glossy end result that I really rushed things. Perfection cannot be rushed lol.

stangkilla1

Oh yea, is my backround showing up on my pages? Or is it just my computer.

lownslocamaro

You can buy Super 77 at Home Depot, I think its in the Paint/Adhesive Section. Spray the surface to be molded and the foil, let the adhesive dry for a couple seconds, stick it, and smooth it out with a bondo spreader.

I wouldn't use an epoxy resin, its expensive as hell. Stick with the polyester resin, and just come back and clear over it. Another option, is once the carbon and resin is down, let it cure, within the tack time, clear gelcoat the parts, then seal it with poly vinyl alcohol(PVA). Pva is used a mold release sometimes but in your situation, you can spray Pva on top of the clear gel coat as it aids in a full cure, afterwarts, you can peel the pva up, and sand and polish the clear gelcoat to the lovely look you desire.

Patrick