Need ideas for lamination panel

Soon I will need to make a panel approx 2 foot x 4 foot to be used as a panel for making thin sheets of fiberglass,

I was considering spraying gelcoat over a piece of glass and then building up from there with a thicker core and then covered with fiberglass. The panel would have a smooth finish on one side, because of the glass I sprayed on, and then approx 5/8" thick overall once pulled from the glass...

Do you think it is a good idea to use a piece of glass to make a smooth panel or do you have any other ideas, overall how do you think this projects sounds?

The finished panel will be sprayed with pva and then I will lay fiberglass on top to be used for other projects that need a smooth face...I feel it would be a quick use of a makseshift mold, without having to do much finishing, sanding if I build up from the other way and gelcoat last...

Wondering if I can even get a cheap cutoff of glass, would polyester eat through plexiglass??

 

Glass will work very well,once coated with release agent.Which leads to the question of why you feel a need to make a panel to lay up on?If the glass is of the sort of thickness that is used for shop windows and similar,it will be more durable than the thinner stuff you might find in greenhouses.I wouldn't expect resin to attack acrylic sheet but would have concerns about some other plastics and would always test a small sample first.A heavy handed laminator who normally pounds the job with a rubber hammer to release an item ought not to be allowed near the project as it will require a more careful approach.

 

I made once poly/fg seats for a canoe on galvanized steel sheet. Worked fine without any release agent but dunno how that works on a long run. With epoxy I have used any flat sheet (usually ply) covered with brown pvc tape..

 

I have a table top that has a thick chunk of virgin tivar uhmw sheet. One side was smooth, we did a light sand of a burr or two and then a light polish (uhmw doesn't really polish but it did smooth out some transport scuffs. After that we just wax and layup straight to the uhmw, pops free just fine and dandy and makes a smooth finish.

Had to box the support table as even 1/2 inch uhmw droops on longer spans. We essentially mounted it to a fabricated flush pallet.

 

Building laminate like used on kitchen bench tops gives a large gloss surface if adequately supported.

 

Just buy a one inch mdf panel and do two lifts of epoxy and polish to 400 grit and 5 layers of wax and release agent. It won’t break.

 

U might be right maybe the glass only would work rather than making a panel from it, I guess my concern is keeping it in the garage, might be heavy and delicate to move around...thanks for the ideas

 

thank you everyone seems like i am on the ight track and may consider some other materials to pull from

 

A surfaced plywood sheet would be safer to use than glass.
I used to make fin panels for surfboard skegs (before they were molded plastics) on a thick glass sheet.
Probably made a hundred panels before it inexplicably shattered overnight.
I think the supports under it must have shifted. I’ll never know for sure, but it pointed up the hazards of using glass.

 

Maybe a hot polyester brew on cold glass upset it? Laminated glass might be more robust, but I stand by Formica sheet.

 

$5o gets you this:
1/4" Thick Clear Tempered Glass for Commercial Doors https://www.trudoor.com/trulite/1-4-inch-clear-tempered-glass/?attribute_pa_size=4-x-34&gad_source=1&gclid=Cj0KCQjw8pKxBhD_ARIsAPrG45nhfEtx1obRlBHEJnPtNLw2oc3hPkhy9x2-iqOi81nHI3245feANV4aAtEYEALw_wcB
You can simply lay it on a sheet of plywood for more safety.

 

When I first started experimenting with resin infusion I wanted to see what was happening on the underside so I got a 1.9 x 0.9 m laminated safety glass as in ex shower screen from a demolition yard for $20, the aluminium frame was nice to have too.
Since then continue to use this for small jobs requiring a glossy finish.

For a very good finish but not as good as glass sheet I have not gone further than melamine coated mdf 25mm, I sort through the pile of cover sheets and select only sheets with one good face from the local plywood and veneer retailer.
These have been $25 for the 1.2 x 2.4m and $30 for 1.8 x 2.4m.