Hey was hoping someone might have some helpful advice. We have been working on infusing a carbon fiber part and we want a super high gloss wet look. We are using Zyvek product GP mold sealer and release and an inmold high gloss clear coat with UV protection for Duratex. Anyway we were advised from our supplier Nexeo to use the #6 release but we had all kinds of fisheye problems with the clearcoat so they recommended wiping down the mold with mold cleaner to reduce the surface tention but no luck. So we now have tried the #3 release and still are getting fisheyes in our clear coat. Yesterday we pulled a part without the clearcoat but are finish just wasn't glossy enough plus we had alot of what basicly looked like fisheyes in our resin. We are using a vinyl ester resin which we buy from US Composite out of Florida. We have done some hand lay-up with this same resin and carbon fiber and the finish has been real glossy for us. We found that the Zyvek #6 when used in our hand lay-up mold even fisheyed with our resin but the #3 when wiped with aceton came out supper glossy but pulled a bit hard. Anyway we are stumpped and not getting a lot of advice from our rep from Nexeo as of yet. Anybody have some helpful tips or advice as we are about to pull our hair out. We have been fighting with this for a very long time and just not winning.

Thanks

Mark

Hi, 

Thanks, we are using a mold made of polyester tooling resin and a tooling gelcoat. The clear coat product is a type of ester based material and we are using vinyl ester resin for our infusion. I have done a bit of reading from lastnights post and have found quite a few people have this same problem. It sounds like the high slip release agents simply don't lend themselves to what we are doing. Sounds like we would do better with a semi permanent release or a product called dolphin wax. Guess I need to talk with my Nexeo rep or someone from Zyvax to see what they might say to this. They sold me the other system knowing what we planned to do but guess they simply weren't aware of all the possible problems. Trust me I am not ready to throw in the towel yet but pretty close to it.

Thanks again

Mark

I have your solution because I have already been pulling my hair out over this same problem. Remember this is only my opinion and it has worked for me. I spray 2 part automotive clear in my mold. Because I use a chemical release called Chem lease EZ (not to be confused withe EZ composites EZ) It is very slick and the clear would just bead up worse and worse as I sprayed more material in the mold to get it to lay down. I remembered a trick when spraying PVA. Set your gun so the clear comes out barely,like a mist. Fog on a layer just so it has applied a haze in your mold.(it helps to add a fast thinner for quicker flashing)

Now wait for 15 minutes or more. Spray another fog coat and wait until it is almost non tacky. Spray with a little bit more fluid flow and wait agin. If you keep doing this eventually you get a glossy coat. Its a pain and slow but you will get there. By doing it this way the slick surface cannot over power the tacky coats that have cured.I leave my clear to cure overnight and then use a fine scotch bright pad and ever so lightly scuff the surface.

I then lay in my carbon and infuse. The parts come out mind blowingly shiney and looking great.

Hope this helps.

Fred 

Fred

Thanks for your thoughts and idea, I was wondering if you know, do we have to be careful in what type of clear coat we use. The stuff from Duratec is a vinyl ester material and uses MEK for a hardner. I'm not familiar with what auto clear coats use for hardners or if they are compatible with vinyl ester resin. It would be nice to find something that we could leave in our gun for awhile yet would flash off quickly when sprayed to help save on clean-up time and expense. We have tried your method with our Duratec clear coat but it's just such a pain since the pot life is about 12 to 15 min. We spend all our time cleaning up and we are trying to speed up production. We have several molds and use a heat box for each but it just seems like there should be an easier way. Maybe we are just expecting to much for this type of procedure. The Duratec rep is suppose to be seeing if there might be a better solution but haven't heard any reply since Monday. Anyway thanks again for your thoughts and insight it was much appriciated.

Mark

As a new member to this site I’d like to say Hello to everyone, as this is my first post.

As the owner of a CNC job shop, one of my customers is a composite company, which caters primarily to the racing industry.  I was reading the posts on this topic and remembered a similar dilemma with molds I was producing for them, mainly delimitation of the mold surface while de-molding and the resulting surface finish.

I recall reading an article several years back reporting on a new process John Deere in collaboration with a composite company in which they were developing the large engine cowls for John Deere farm tractors. The components were a one-piece fiberglass cowl that was produced using chopper guns and a secondary clear coat finish after de-molding. This proved very time consuming and they were having quality issues as well.

The solution came by using a clear thermal forming plastic (similar to “clam-shell” plastics used in packaging such as PETG) that was vacuum formed into the female molds, then the chopper guns applied the fiberglass/resin complete with color mixed into the resin. Reportedly, the production time was cut significantly, as the parts didn’t require complete cure before removal from the molds, and the plastic created the clear coating they required.
I was wondering if this process has been tried by anyone else in this forum in resin infusion?
I hope that I didn’t “hi-jack” the topic, and I look forward to your responses!

Welcome Mark,

Hello

Isn't this the technic used in the Bricklin cars. It was just aweful. Two dissimilar materials that had different expansion rates. The bodys were all wavey and got worse over time.I believe hot tubs use the same process. But John Deer must have done testing. (I hope)

Fred