best/fastest way to make geometrical shape molds? (and panels

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#1

I build a lot of geometric stuff and instead of going through the painful process of primering and sanding, i was wondering if there was a quick way to make panels?

for example, flat pieces are super easy, and can be made on glass (i assume you can use plexi/acrylics too) by just waxing the surface. Maybe even some aluminum or steel as well (may require buffing?)

but what if I wanted to make, lets say a “square U” channel? I would think combining 3 panels and joining them would be the easiest way, but what material/ how would you go about doing this? The idea is to speed up the mold making process by trying to eliminate surface prep to bare minimum.

for instance I prefer glass since its more durable to scratched then plexi/acrylic. so i would make a 3 sided wood frame, secure the glass panels to each side then join them by recesscing them into pockets in the wood and making endcaps that hold them in place… now the question is how would you fillet the corners so they arent sharp perpendicular edges?

I guess another method could be using aluminum and bending it into a U shape on a brake (using a round pipe instead of the straight blade to create the radius) then sand/buff out the scratches (better sanding the whole panel)

For the seasoned pros, what would you do, and do you have any tips/tricks on making “facetted panel” molds?

Also how can you achieve a high gloss finish on both sides? can i wet lay up CF/FG then sandwhich it together with glass on both sides and vacuum bag it?

#2

totally a novice here… I’d say your on the money for using the glass for the double sided finish… for the “U” channel I’d try PVC tubing in the diameter needed and cut in half then butting the glass, plexi, steel up against the pvc… Using clay to fill in the seams and just wax away… if needed you can get the PVC in a size smaller diameter to make the corresponding positive to lay on top… You try using plexi glass heating it up till you can bend it, using a brake…
just my 2 cents…

#3

For one of my project, to reduce mould cost, I have made a “U” shape with 3 flat panels of plexiglas.
The panels was glued with an special glue (UV glue).
Works fine

#4

I’d probably use some type of caulk on the edges. They make all types from normal 100% silicone to fire retard caulk. After that dries just wax, pva, and do your normal things.

#5

Do a google picture search for “wax fillet” and you get an idea.

#6

How did the edges come out? im assuming each part needed some finishing after demold?

did you sand? the caulk after or were you able to feather it out well enough that you didnt see the transition from the caulk to the glass or was the seam visible still?

this is some interesting stuff, I’m gonna try it out, thanks for the recomendation

#7

does anyone know where i can but fillet wax in the US? when i search google only easy composites in the UK comes up… i do have the regular grey Plasticine but its pretty stiff so i was hoping to find something with a softer consistency…

#8

Don’t take my advice. I’m not sure if caulk would work.

But there’s many different kinds. Whatever the kind a trick is to take a cup of water and put a dab of soap in the cup and stick your finger in and then wipe/feather the caulk when it’s still wet. This gives a nice edge and it’s uniformed too depending on the pressure and speed of your finger.

You could I guess use grout as well then clear over it or something to seal. I don’t know, just tossing ideas out there.

#9

I use these at home sometimes…