Vacuum Veneering Tutorials

[Ted Hunter]

On our skateboard longboards I actually tell people if they want camber along the length of the deck (crown) to actually bend the foam mold as you are pulling the air from the bag. The mold already is convex in shape across the deck (deck is upside down on the mold)

By putting two 1" to 1-1/2" spacers at either end of and underneath the deck on the outside of the bag. It is easy to press down in the middle of the deck while pumping the air from the bag. Once the air is removed the pressure inside the bag prevents anything from moving. The end result is a laminated form with both concave and camber from a foam mold.

Ted

 

[norman]

Hi WH37

I used two types of pack for the beans, plastic to which I applied vac to hold shape, the other cotton to even out pressure on the veneer inside the bag to form shape. Never tried cling film could you contain a vac within it?.
Have fun
Norman

 

[Chris Knight]

Norman,
I meant that I would put sand inside clingfilm and shape it (to some arbitrary shape for this test) and use the plastic wrapped sand as the mould for the veneer, all inside my vac bag.

 

[norman]

Chris

would the sand hold its shape under pressure?
Thats why i used a vac to lock the beads to the shape i wanted. inside a plastic bag with a good seal.
Norman

 

[Chris Knight]

Norman, I may have misunderstood your original post - I had envisaged that your bean bag was inside a vac bag, I thought that in effect I was simply substituting sand for beans.

I now wonder if you had an evacuated bean bag inside another vac bag?

 

[MikeW]

Hi Chris,

I think Norman is using the bean-bag beads to make a form, one that can be shaped, yet under the pressure of vacuum--it's own bag--it would hold its shape.

At least I think so. Correct, Norman?

If so, I've never tried it but sounds like it would be interesting to try. I have used sand bags like Chris suggests, but these are used as a conforming and even application of pressure--moldable cauls, so to speak.

Take care, Mike

 

[norman]

Mike/Chris

Yes mike
"using the bean-bag beads to make a form, one that can be shaped, yet under the pressure of vacuum--it's own bag--it would hold its shape. "

the cotten bag was used as a caul to give even pressure.
Usefull to take an impresion from item too large to fit inside bag and obtain vac seal.

Chris
you could use sand , but have never tried to make form only used as a caul over the top.

I used this when dealing with some oyster work and needed to preform the oysters around a large moulding befor fitting into place.

Norman

 

[Chris Knight]

Mike,Norman,
Thanks for the clarification.

 

[Steve Maskery]

Aha!
Went into B&Q today, and what did I find? Pink insulation foam. Very firm (firmer that the polystyrene next to it). Made by Knauf. R-value of 1.8, whatever that means.

Anyway, I bought a pack of four slabs for £20 and I'll let you know how I get on.

Also I found a reel of iron wire in my workshop. No idea where it came from, but it looks just the job. I just need a transformer now.

Cheers
Steve

 

[MikeW]

Cool Steve--and I am interested as well. My youngest and I are going to make some snowbards and cutting/shaping with a hot wire would make the initial work go faster, I would think.

Take care, Mike

ps, the "R" value is a relative index of thermal resistance...

 

[Scrit]

Also I found a reel of iron wire in my workshop. No idea where it came from, but it looks just the job. I just need a transformer now.

Oh dear, there goes the kids' Scalextrix controller..... :lol:

Scrit

 

[Ted Hunter]

Cool Steve--and I am interested as well. My youngest and I are going to make some snowbards and cutting/shaping with a hot wire would make the initial work go faster, I would think.

Take care, Mike

ps, the "R" value is a relative index of thermal resistance...

Mike
If it is a one off foam mold you are wanting to make for the snowboard. I recommend shaping it by hand. The reason I say this, for a hotwire setup you will have to make guide templates for the hotwire to follow, that either need to be made of masonite/coated with a heat resistent tape or built from a material like aluminium that will not burn.

By the time you make the hotwire templates you could have shaped half a dozen foam molds using tools that you probably already have.

The hotwire process is fun but for one off shapes its a lot of work.

Ted

 

[Steve Maskery]

That's useful info, Ted. I had envisaged having an MDF baseboard with MDF profile sides to guide the wire. I found some useful info from the www from a bloke who did aeroplane wings, using rechargeable batteries (seems a helluva lot cheaper than the RS tranformer at £200+).

I'm finishing off a crude bed with which I'm thoroughly bored, but will embark on the sculpted chair back ASAP.

Cheers
Steve

 

[Adam]

How about one of the cheap power supplies from Farnell?

I managed to borrow one when I was doing this:

See this post here: https://www.ukworkshop.co.uk/forums/viewtopic.php?t=5604

Give me a shout if you need to know anything.

Adam