I am building a Porsche 997 for the EEC in 2008. It is coming on nicely except for one problem.
When I am applying the "Gel" coat to the silicone mold I get a "Fish Eyeing" effect which prevents covering the surface with gel coat evenly and smoothly. As a result I get buubles etc in the body surface.
Any ideas how to prevent this?
I am using Ampreg22 resin.

Hello Erlo

The fisheye effect you mentioned is a logic effect of the silicone mold.
Silicon is ideal for mould making as hardly anything sticks to silicon....but the downside is this .........also goes for your fist gelcoat..

The fisheye effect is simply the result of the capilar force/ surface tension within the epoxy resin. It wants to stick together leaving small holes in the gelcoat.

The solution is simple. Apply the first gelcoat with a soft brush, and keep brushing with gentle strokes spreading the epoxy evenly and smoothly in the mold until the gel coat start to set (± 20-30 minutes) mix some new epoxy resin to fill anay gaps if the first layer gets to sticky.

You will always have some small holes/fisheyes in your topcoat, but these will be filled with the next layer once you'll start laminating. make sure that the gelcoat has set properly so that the surface is still sticky (like cellotape)....but does not produce threads if you touch the surface.

Good luck

Hello Tamar

Thank you for the feedback I guess it is a matter of patience and slow deliberate work.

Kind regards
Erlo

Had the same problem and almost threw the cast away....
then i decided to go ahead with the laminating and see what happens.
before actually putting on the fiberglass, i put down a layer of epoxy (Green)
waited a bit and then laminated as always. The result -
GREAT,- the new layer fills the "fishes eyes" and all is good!







good luck!!

Fola

Hi guys, well it seems we're on the right track now. We were told to get a type of wax from our supplier, and to polish the mould, which naturally reduces its tendancy to release items slightly, but, also stops the fish-eyeing effect very well.

So, what this means is, we now have a very accurate and correct Porsche 997 GT3, as well as the very up-to-date Ferrari F430 GT.


Cheers.

Big Al

Hi Erlo,
who are you really??
I mean in the real world.... ; -)

I am interested in what you do the Porsche looks good....
what was the original body? How much does it weigh.... would it
be expensive to get one??

Regards,
Fola

Hi Fola

Replied to you via e-mail, let me know if get it.

Cheers.

Hello Erlo and all other Laminators

A simple tip, got it from the nice lady that makes the molds for Le Mans Miniatures, its actualy meant to preserve your molds and make the "release" easier.
Nick's been using it sicne he started laminating and it helps also a bit against "fisheyes"

LMM "dusts" their molds with talkpowder, best brand...Zwitsal



p.s this is not a joke

Mr T, check U2U pls..

Big Al

Hello Tamar

Funny enough my wife suggested using talkpowder when I originally encountered the fish eye thing. Clearly a lesson here that she knows things that I dont know of.

Kind regards

Erlo

....what their true knowledge is will always remain a mistery...to men