Need ideas for lamination panel

[ondarvr]

For a glossy finish use glass, no PVA is needed, and will only create surface imperfections.

You do need to thoroughly wax it though, you can get a very good bond to glass if you don't.

 

[wet feet]

I've seen a couple of excellent examples of adhesion to glass.An eight foot panel was used as the surface for moulding prepreg at 120 deg C.The heat transfer through the vacuum bag wasn't as efficient as the conductivity of the aluminium table the glass sat on and it is believed that this caused thermal expansion from below to crack the film of release agent (not a wax) that had been applied.I wrote believed because the glass was chipped off the carbon panel,as the carbon was more valuable.Another piece of glass was acquired and prepared with extreme diligence for the same process and exactly the same thing happened again.The previous ten panels had been made with ambient cure wet epoxy laminates and gave no problems at all.

 

[ondarvr]

And there are two different sides to a pane of float glass that will give slightly different results. Sometimes the glass is marked when new, but after that I'm not sure how you can tell.

 

[TeddyDiver]

What do you mean by "surfaced" I am trying to save some effort by using something flat and glossy to simply spray PVA over to make the panel from...

Film faced plywood. Fenol film on the surface. At least epoxy doesn't stick to it..

 

[aaronhl]

Did someone say acrylic would work well if I spray PVA over it first? I could actually use the acrylic for another use after so it wouldnt go to waste...

 

[ondarvr]

PVA typically creates an imperfect surface that will need attention to make it look good.

Old glass can be found easily and sometimes at no cost. Sliding glass doors work well.

 

[redreuben]

I’ve seen glass stick up on several occasions but also seen it work ok. I prefer full gloss melamine/formica. Seems to take wax better, easier to handle and store and much cheaper for bigger sheets.
You can also cut it and glue it and fillet it to make more complex shapes.

 

[aaronhl]

I’ve seen glass stick up on several occasions but also seen it work ok. I prefer full gloss melamine/formica. Seems to take wax better, easier to handle and store and much cheaper for bigger sheets.
You can also cut it and glue it and fillet it to make more complex shapes.

That is good information for potential future projects even, as it could be used as a temporary mold

Maybe a little off topic, For more complex or compound curves, would I be better off using thin strips, seems like wood panels or fiberglass panels may only have so much bend to them... ?

 

[ondarvr]

It can stick to glass, but only if you don't prep the surface correctly, as in, not following the directions for that exact mold release product as written on the container.

 

[redreuben]

That is good information for potential future projects even, as it could be used as a temporary mold

Maybe a little off topic, For more complex or compound curves, would I be better off using thin strips, seems like wood panels or fiberglass panels may only have so much bend to them... ?

I have not experimented with compounding, my reference to complex shapes and filleting refers only to making moulds in flat planes as in internal furniture or bulkheads.
I have wondered what could be done with contour foam bagged onto a panel and then tortured without the internal skin but have never tried it.

 

[redreuben]

It can stick to glass, but only if you don't prep the surface correctly, as in, not following the directions for that exact mold release product as written on the container.

This is true, and usually takes the form of applying wax coats on one after the other without adequate drying time between coats.
Four coats of wax one after the other is effectively only one coat of wax.
Rookie mistakes.
That said I still find melamine/formica more forgiving.

 

[wet feet]

I have not experimented with compounding, my reference to complex shapes and filleting refers only to making moulds in flat planes as in internal furniture or bulkheads.
I have wondered what could be done with contour foam bagged onto a panel and then tortured without the internal skin but have never tried it.

I suspect you would get reasonable results with quite gentle curves but for tighter curves it might be better with honeycomb or even over-expanded honeycomb.The downside is the higher probability of later delamination as a result of the much smaller bonding area.

 

[redreuben]

I suspect you would get reasonable results with quite gentle curves but for tighter curves it might be better with honeycomb or even over-expanded honeycomb.The downside is the higher probability of later delamination as a result of the much smaller bonding area.

I suspect the main limitation would be the grp skin rather than any particular core material

 

[wet feet]

I suspect the main limitation would be the grp skin rather than any particular core material

You might find it enlightening to seek out information about the early days of Formula 1 carbon monocoques.A number were made by laminating flat carbon/honeycomb panels and then routing grooves at the fold lines.The honey comb beneath the grooves was filed with epoxy and the panel carefully folded around a jig.One the initial cure had taken place,the jig was extracted and a band of carbon tape was applied over the inner surface.It helped if the initial cure of the skins wasn't too far advanced.Glass might be a lot more compliant.

 

[aaronhl]

I looked at a few materials Home Depot has...noticed the melamine is all orange peeled up close...was considering acrylic but felt the Smooth MDF for 4x2 foot piece @ $7 would be worth a try. I could see a refection in the smooth MDF panel, I might try to spray PVA over it and see what I can pull off...if it doesnt get soggy on me