Carbon Console Overlay

putting the carbon face down on the table and doing a vacuum wet layup will almost always create voids and air pockets/bubbles in my experience unless you resin infuse. did you use bleeder/breather cloth on top of the peel ply? did you lose vacuum or did the resin gel up before vac was pulled? if you can try thinner resin that might help?

I just read that you used alcohol and the spots remained. that sucks i've been there.

if your show side did not meet your expectations. I would sand the "backer" side of the part if possible and throw a coat of resin on it to see how that looks. if your just making a flat panel that is.

 

I built the first panel as follows.

peelply on table
6 oz woven backer
5.5 oz carbon
PetG 0.030" plastic caul and force out bubbles
Breather around edges and vacuum on the part.

too many holes in the part; did same thing again second day

sanded to flat a few high n lo spots

white spots all over the place

 

hmm that sucks.

so the next thing id try is to "skin" one of the panels you made. wet out the part with a thin layer of resin, let it gel to where you can put your finger on it and it will leave a fingerprint but no resin on your finger. place a layer of dry carbon over the resin, either press it down gently with a sticker squeegee or bondo spreader or you could vacuum bag it for a minute. you can let the dry carbon cure to the part or mix up some resin right away and use the spreader or squeegee to lay out resin on the dry cloth. paint brushes and roam rollers or foam brushes in my experience introduce air bubbles, however, if you do see air bubbles you can use a hair dryer or heat gun to pop them. i've had very good luck adding thin layers of resin on top of each other while the layer on the part is still slightly tacky. then when you get a nice build up of resin you can sand and level in between coats. or just sand flat the entire part and use an automotive 2k clear coat for the UV protection.

 

It looks worse than this up close. These are the bigger bubbles.

 

Much of my market is cosmetic carbon parts, I walk people through this every day.

Customers like I linked earlier do this stuff on a contuous basis.

You are making this much more difficult than it needs to be for a flat carbon panel.

You either use an in-mold coating, or do lots of work later. You need a uv protective clear in the end either way, so start with a glass surface and sunshield. Hand lamination or infusion works.

I make demonstration panels for industry shows (a thing of the past) and Customers all the time.

 

I bought a clear uv aerosol finish that cost like $140 for two cans.

what is the benefit of sunshield versus a spray on after?

if my vac table is pretty decent, is the waxing the issue?

don't you wax the glass, too?

I have a decent mould surface. Finding a 40" square piece of tempered for one part is a pita.

Thanks for your contributions.

I have given up on that part. I might use it for some solid glass panels I need that get traction paint..

 

The stuff in cans tends to be pricey for what you get, and it really isn't that durable or easy to repair. Plus carbon surfaces tend to have all those defects, and many more that you won't find until you try to apply those coatings over it.

You can find old windows for a mold surface that size dirt cheap, or even free. They get thrown out all the time.

For cosmetic panels most people switch to polyester, it will flow far better than epoxy and leave fewer defects. You already have a bunch of epoxy though.

I've made panels like that out of just Sunshield, brush it on the glass and let it cure. Generously wet out the surface again, lay down the carbon, then apply more sunshield as needed to wet out the carbon. Roll the air out with care so you don't mess up the weave, repeat until you've put all the layers of fabric down. Epoxy tends to be sticky and viscose, so it's more difficult to wet out the fabric, but it can be used if you prefer to not use Sunshield for the entire laminate.

You could infuse it with Sunshield if you wanted.

 

Okay.

I am going to get a piece of glass from a lady for $35.

1. Do I wax or pva the glass or will the sunshield release cleanly no waxing? And I can brush it on? I was avoiding it because I thought I had to spray it.

2. If I use epoxy over the sunshield, would you use perforated release film? The perfs are 10mm squares. I am just nervous the breather on the peelply will a bear to release, but since I had all the air bubbles also worried the release film will hold air in.

Thanks.

 

Sorry to jump in on this, again.

I don't know much about sunshield but I think its a polyester resin with UV inhibitor, correct?

A while ago I made or attempted to make a 2'x2' carbon fiber sheet to be used for pickguard material for my guitars. I used epoxy and a sheet of glass. I opted out of vacuum bagging because it wasn't structural and used weight on top to keep some type of pressure on it. I also assumed I did not need to use wax or PVA. this was a HUGE mistake that I made. the epoxy stuck to the glass and laughed in my face about it. the glass was probably about 3'x'3 in size and was pretty heavy. I couldn't salvage any of the carbon at all so I had to completely destroy it to fit it all into the trash. breaking non tempered glass that has a thick layer of carbon fiber bonded to it makes for a super dangerous mess. glass was everywhere.

could've been my epoxy or something with the glass itself but if its not going to hurt anything but a little time I would wax the glass for sure and if I personally did it again, i would PVA as well.

about a month ago I did similar as you with a sheet of carbon 12k. I used melamine for my flat vacuum surface that I waxed and brushed on PVA. I brushed a layer of epoxy onto my flat surface but didnt let it kick off ( probably should have), layed 2 layers of cloth down and saturated them with resin, applied peel ply and bleeder cloth and then vacuumed. the result was not good as you can see in the first pic. lots of pin holes. so I sanded the crap out of it and washed it with water and then dried with compressed air. it still looked bad so I just started piling on a few layers of epoxy and it ended up looking near flawless ( the second pic) it does look like there are some pin holes put those must be dust or something else because the final result was flat and glossy smooth.



then the skateboard I built using a foam mold and vacuum had a lot of issues as well. I sanded the crap out of it and did my best to fill the holes with epoxy. it looked a little better but still not great. its super hard to tell in this crappy pic but I ended up adding a green and red pearl to the 2K clear coat. in the sun the tint of the board changes from red to copper to green. the best part is that you cannot see any of the imperfections any more.


I say all of this because i hate to see you give on the panels that you already have made. a little more time, sanding, coating and clearing could still save your parts. Tint your epoxy to match the carbon and drop fill the pinholes, tint the clear, or something else.

just hoping to help.

-Mark

 

Wax the glass, PVA isn't required and adds more work to the final steps (there is a way to use it with better results though). Follow the directions on the can of wax. All waxes will work, but the directions for use can be very different. You can actually get a very good bond to window glass if you don't wax it.

Brushing Sunshield works, it usually takes two applications. The first one may not want to cover the surface completely, but the second one will fill it in. There are a few tricks that help sometimes.

Carbon is relatively difficult to wet out due to the very small fiber size, and the tightly packed fiber bundles. This is why it's so common to have so many small defects (air) next to the mold surface.

Add in that epoxy has a higher viscosity so it doesn't flow as well, and the likelihood of defects is even higher.

The nice thing about using a clear in-mold coating on a glass surface is that you can see what's going on during an infusion or hand lamination. This allows you to take some actions during the process to improve the outcome.

 

Well, I tried the Sunshield in mould. What fun.

First thing that happened is a bunch of fisheyes. Had to pull all the Sunshield off and then redid it after about two hours of cleaning.

I left a slight swirl of partall#2 on the glass to help with the fisheye and because I was doing a sample.

I sprayed the Sunshield and only had a couple fisheyes on the 2nd try.

Then I must have undercatalyzed because it was taking forever for the Sunshield to firm up. Finally, after an hour, I just went for it.

I poured epoxy on the Sunshield. Big mistake. I needed to wetout on plastic and move the wetted carbon to the Sunshield. In the middle, I had ridges of epoxy and on the edges; I forced the Sunshield off the glass. The sample failed.

I catalyzed 172g of Sunshield with 3g of catalyst or 1.8%. I think next time I will go to 2.5% as my shop is a bit cool and the longer the Sunshield sits; the more crap that falls on it. Nearing the end of the build and there is quite a bit of dirt everywhere. Then I will wetout the carbon away from the mould and roll it onto the Sunshield; although it will be important to get it just right..it won't likely move much after...then I will probably peelply and bleeder and breather on the mould.

Any suggestions are welcome. I tried to sand with 400 grit and it really showed my unevenness and Sunshield missing on the edges...all due to wetting out on undercatalyzed Sunshield..

 

Dang.

I told you there were techniques required for its use and to let me know if you planned to go that route.

Paste wax is a must, and applied correctly.

Spraying is done with a small tip and lots of air on the first pass or so. Acetone can be added for this first bit, it helps to eliminate fisheyes if used correctly.

The chemistry is not compatible with epoxy in a liquid or tacky state, so I hope it cured sufficiently before epoxy was applied.

Letting it cure yields a tack free finish that allows repositioning of the carbon as much as needed.

The good part, is that if the bond is good, after a light sanding you can coat it with sunshield and sand it smooth, most of the time you'll never notice any defects .

 

well, this was just a sample

the Sunshield was not kicking very fast and so no way could I wetout above it easily; some of the epoxy forced the Sunshield off the part

what rate would you use by weight for say 67 degrees? Low humididity.

I'd like to try the acetone trick. How much acetone for say 172 grams of Sunshield?

Can I fix a hole or fisheye with simply a dropper of Sunshield?

thanks for any advice...I didn't realize I needed more help

I think the biggest issue is it didn't tack up right at 1.8% by weight.

 

2% by weight is good, you can go by volume too.

Acetone up to about 10% can be used, but less is always better.

If you get a few fisheyes you can put a drop of sunshield in them. Or, I sometimes quicky brush over them and lightly spray it again.

It may take a little while for it become relatively tack free, don't hurry it. Find something else to do for a while, or spray it last thing in the day and start again in morning.

 

just that we have a lot going on now; so there is always dust flying of various kinds; wood, composite cores; forced air heating system and 19 degrees overnight so heat runs a lot stirring air right in that area