Balsa Foam

[DEL]

Hi all. Has anyone here had experience of this product?
I'm particularly interested in choice of glue an sealing prior to painting.
Cheers
Derek

 

[arj]

Hi Derek,

While I haven't used the material, this scan is from Martin Windrow's book "Advanced Terrain Modelling" (page 129), which should answer both your questions:-

Cheers,
Andrew

 

[valiant]

If joining large pieces, Ive used silicon sealant as an adhesive. This doesnt give a hard line of glue if youre sanding.

For sealing prior to painting, make a 50 - 50 mix of PVA and water, then paint a couple of coats on, allowing drying in between.

 

[DEL]

Andrew, Steve,. Thanks thats exactly what I was looking for.
I'd heard it was similar to florists oasis foam and was concerned about it absorbing glues and paint.
Cheers
Derek

 

[yellowcat]

Here is a video on balsa foam:

 

[DEL]

Thanks Felix. I see he raises the issue about paint near the end of the recording.
Clearly the sealing even prior to priming is critical.
My interest in this is that it's density allows for a very crisp finish but given its cost compared to other foams it's important to get it right without to much experimentation.
Cheers
Derek

 

[valiant]

Del - try getting hold of some insulation material, such as Kingspan or Quinntherm. Its virtually the same as balsa foam.These come with a foil covering which can be peeled off, then the foam can be sanded and shaped really easily. Its very dusty. so probably best using a filter mask and outdoor sanding, but you can get a 6' x 4' x 4" sheet for about £40, which should last a lifetime!! It also comes in thinner sheets. I have a builder mate at club, who keeps offcuts for us to use.

 

[chippy]

Derek Shoot round to Ron's I bet he must have off cuts of Insulation sheets hanging around if only to keep him warm in his new woodland hide out . I wouldn't use silicon as an adhesive as any over spill will not sand down , something like no more nails or gripfix that hardens up would be better .
chippy

 

[valiant]

The silicon sands down quite well, as when you squeeze the pieces together, there is only a very thin film - the problem with adhesives, like "sticks like ****", is that it does leave a hard seam which can be a "bi**h" to get rid of! PS - use coarse (like 60s or 80s) paper for shaping