The only thing that may help ist to lay a resin layer as first layer in the mould. Than you can such the entrapped air into the laminate and get a void and pinhole free surface. But it is a pain to lay a resin layer witout entrapped air in the mould. A resin mesh will not help, it will make it more worse.
You can only wipe rein with acetone over the part that the pinholes will be filled before clearcoating.
Reviving an old thread as I’m currently experiencing these exact issues. carboncactus did you ever find a solution to the pinhole problem?
I am having the same issues as well. I have changed curing process and tried different materials. I am thinking the only cure to this would be an IMC but not sure what product to use. When I clear my items they look identical to the picture at the start of this thread. I was told to spray an extremely thick layer of clear and with a rubber glove on rub it around to try and fill the pinholes. Let that cure and sand then spray one last layer of clear and it should eliminate all of the pinholes. I personally have not tried this yet.
Can you get Duratec topcoat where you are? The Duratec topcoat is really easy to fill pinholes with, and in fact there’s no real sanding required. All you do is spray it on as you would normally, so 1-2 dust coats with 2-5 minutes between coats. Then do your first wet coat, and it is after applying this wet coat that you can use a squeegee or a roller to force the topcoat into the pinholes. Then continue building your film thickness as per normal, and you shouldn’t have any issues with porosity from here. If you do, just allow it to cure and then rub it up with 180 and go again.
Any final finishing should be as easy as a quick flat with 800 then 1200 and compound. Man I love the stuff!
hi guys,
wouldn`t it be better that u use an out of autoclave prepreg that u gets pinholefree results with a clear resin??
i know exactly how long does it takes and the work/cost involved restoring a prepreg part with pinholes.
regards
mehmet