+x

 

Massimiliano - 5/11/2020 9:10:54 AM

+x

 

Hojo - 5/11/2020 7:49:44 AM

+x

 

oekmont - 5/11/2020 7:33:08 AM

I think the problem was not the little porosity a mould sealer would be able to seal. Your mould is full of small open air pockets. The closeups show many white pieces of gelcoat stuck in the tooling gelcoat, as well as goosebumps on your final part. The edge of your mould doesn't look good either. There were a lot of mechanical loking points. Some of them were too much for the tooling gelcoat. My guess is that you moulded from a bad plug und sanded the mould a lot, right? If so, always try to make the plug as perfect as possible. Sanding the mould too much is always the risk of opening some air bubbles in the tooling gelcoat.

A good point, its probably a void under the gelcoat. Often when you hand laminate without vacuum you will get a void from the material bending around a corner. You can add a mix of resin and cabosil and put this around the edge to help avoid these types of voids. You can also do a thin fiberglass skin on the gelcoat and inspect for voids after it cures. If you see any voids you can cut them open with a knife and they will fill with the second round of lamination. This is why I prefer infusion or prepreg/autoclave for tools. Quality is superior in so many ways to hand lamination.

You mean applying by hand the tooling gelcoat and then infuse the reinforcement?
Will not the vacuum deform the thin gelcoat where the plug is filleted with the filleting wax?

+x

 

Hojo - 5/11/2020 9:17:10 AM

+x

 

Massimiliano - 5/11/2020 9:10:54 AM

+x

 

Hojo - 5/11/2020 7:49:44 AM

+x

 

oekmont - 5/11/2020 7:33:08 AM

I think the problem was not the little porosity a mould sealer would be able to seal. Your mould is full of small open air pockets. The closeups show many white pieces of gelcoat stuck in the tooling gelcoat, as well as goosebumps on your final part. The edge of your mould doesn't look good either. There were a lot of mechanical loking points. Some of them were too much for the tooling gelcoat. My guess is that you moulded from a bad plug und sanded the mould a lot, right? If so, always try to make the plug as perfect as possible. Sanding the mould too much is always the risk of opening some air bubbles in the tooling gelcoat.

A good point, its probably a void under the gelcoat. Often when you hand laminate without vacuum you will get a void from the material bending around a corner. You can add a mix of resin and cabosil and put this around the edge to help avoid these types of voids. You can also do a thin fiberglass skin on the gelcoat and inspect for voids after it cures. If you see any voids you can cut them open with a knife and they will fill with the second round of lamination. This is why I prefer infusion or prepreg/autoclave for tools. Quality is superior in so many ways to hand lamination.

You mean applying by hand the tooling gelcoat and then infuse the reinforcement?
Will not the vacuum deform the thin gelcoat where the plug is filleted with the filleting wax?

no, when I do infusion tools I do not use gelcoat. If you want to use gelcoat and infuse, typically you need to put down a skin layer down, typically fiberglass so you can see air bubbles