UV protection?

General Composites Discussions Products Talk
#1

Hey I was wondering how do u guys protect your pieces from uv rays,.
i did some parts for the interior of my car and was wondering, Are some epoxies already UV protected? or do u spray some sort of clear coat on?
right now i do about 3 layers of epoxy and then spray on some krylon clear coat to top it off and get a glass finish.

It says the krylon protects from yellowing is that the UV protection

I’m worried that later on, the pieces will start to yellow so i do about 6 layers of clear coat! AM I crazy? or should i do this?

im just wondering what you guys do to protect for the long term?
i know interior car temperatures get realllllllly hot so what should i do?
thanx
JOE

#2

Non yellowing doesn’t equate to UV protection. Usually if your clear coat is UV protected, it’ll say so on the label. 3 coats should be fine. You really don’t have to go nuts on that. Also, most epoxy resins are not UV protected. Again, if it is, it’ll say so clearly on the label. Good luck.

#3

any clear coats that you recommend,.?
i have no clue where to even look,.
see,s that everything is not uv protected,.
JOE

#4

The best stuff would have to be the Diamond line by PPG. That is damn expensive though. A cheaper alternative is something called Clearex. I’ve never tried it but if you want I can try and find out where to get them.

Other than that I don’t have any specific recommendation. Any clear gloss coat with UV protection should do.

BTW, all of the stuff I’ve mentioned do not come in spray cans. You’ll have a compressor and a paint gun. If you don’t have access to one, just go to your local auto parts/paints shop and get the stuff they have on the shelves.

Evan

#5

i know it sound dumb,.
but what about krylon 1305 uv protective spray?
im looking for an easy way out,…
would this be up to par?
or is it crap,.
joe

#6

That looks good Joe. Just make sure to read the label to see if it’s compatible with fibreglass/resin finishes. If you’re unsure, spread some epoxy on to a flat surface, let it cure and spray it with the Krylon and see if there’s any adverse reaction.

The likely hood of something bad happening is very small but you don’t want to take any chances.

Good luck,
Evan

btw, did you get the decal?

#7

I have heard of carbon fiber hoods cracking on the surface. Is this caused by the clear coat delaminating from the epoxy resin?

#8

Sorry I’ve been gone. But back now.

It could be of many factors. Of the ones that I can think of are:

  1. Unproperly cured epoxy. Not post-cured with the correct heat.
  2. Crappy resin. Too brittle.
  3. The one you have stated which is the resin itself not laminating to the fabric. The separation causes the resin to lose its strength property and crack under stress.
  4. The entire structure endured too much stress which caused it to break down.

If you hear it happens from carbon fiber hoods, chances are the hoods aren’t installed properly allowing the wind to enter and push the hood upward at high speed. This causes the hood to vibrate and flex to the eventual point of cracking. Sometimes properly installed hoods will still crack because the hood is not structurally sound enough (aka cheap hood)

UV protection only protects the resin from yellowing out. It won’t protect the resin from cracking.

#9

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