# Curved laminated forms



## sven (Feb 7, 2012)

Here's a little trick I used recently. 

Needed to make a curved detail out of sapele which cannot be steam bent that easily. I happen to have some sapele veneer (0,5mm thick) so I decided to laminate 20 layers to get ~10mm thick detail (didn't bother to go thicker...). I used 2 component slow curing epoxy resin because it takes some time to apply 20 coats of glue and getting it under pressure...

What you need is some fire hose, air compressor with pressure regulator and bunch on air connectors (additional manometer is recommended). Just install air connector to fire hose (use two BIG washers, so that it wont fly out under pressure) and add some sealant to prevent minor leaks. I was lucky to find two old engine oil filters for plugs (for firehose) but turned plugs might be needed if some readily made object cannot be found. Plugs should have some edge or lip (like oil filters have) to prevent it flying out. I was also thinking about using condensed milk cans but imagine the mess if ...  

Facade of the press jig must be perfect but the back side can be quite rough, pressure inside fire hose will even it out.

So glue up your laminates, pack in plastic, throw in jig with fire hose on backside, clamp down other half of the jig. I used threaded rod and some thick offcuts to clamp it town. C-clamps might work too but there is lot of pressure and they might just fail. Threaded rod and offcuts is the cheapest solution (I only made 3 clamps using threaded rod because I did not have any more in shop and really didn't bother to go to store for that). 

Air line form compressor to fire hose should be thought out before (additional manometer is handy). I turned town the pressure regulator so that i had 2 bar pressure in fire hose and 8 bar was left in compressor. As the fire hose leaked a little bit, the compressor kept constant pressure through pressure regulator. I must say that my brand new compressor has bigger leak than the fire hose...

!!! Be careful with air lines, once had feed line attached straight to compressor and also didn't check valve position... got some nuts flying...!!!

Ok here are some pics.















































Whaddaya think?


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## woodbutcher360 (Jul 1, 2012)

Looks very nice but I have a question. Did you build the form to use air pressure as a clamp?


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## Dave Paine (May 30, 2012)

I think this is interesting. Did you try this with just the form first?

I have only attempted one lamination. My test project was only about 12 in but tighter radius than yours. I was using 1/16in strips of walnut.

Although my form did not touch everywhere, I was able to achieve a decent glue-up.

I am just wondering the criteria for when the air hose becomes valuable. As an engineer I love such contraptions, but it does add a lot of time to a project.


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