The Unofficial Airfix Modellers' Forum

Seems the only way I am going to get on with a very stalled PZL.37 build is to try my hand at plunge moulding a new nose glazing section. What I am curious to know is what sort, if any, kind of sealant should go over the balsa master before I plunge it through a section of clear plastic card? Any advice would be helpful.

I'm not sure about sealing balsa nowadays. Years ago, Alan W. Hall used to use a home made mix of talcum powder and cellulose dope! I'd probably just try several coats of primer myself. Prime, sand, prime, sand, .......

David

I used to use carbody filler on the balsa when I used it. Applied and sanded really smooth.

These days I use polymer clay for shaping of the male part. Polymer clay is better known by its trade names of FIMO or Sculpey.
I find it does a far better job

PS; don't forget to make the male mould slightly under size, to allow for the thickness of the clear plastic.

Yes Fred, thanks so much for the advice. At some point soon I am going to get on with this. I hate having a stalled build taunting me from the workbench.

Well, I have the balsa master all made and primed, but with acrylic paint. Is that going to cob off on the canopy or should I use floor wax? Or is that going to stick as well?

Don't use Klear/Future, its softening point is below the heat needed to make most clear plastic malleable enough to mould.
I can't say bout the paint as I've never used it with heat.

Drat. Ah well, I guess I better either a.) find something suitable to seal the part or b.) start digging through my stash and see if I can find my complete PZL Los kit, I wish I had never bought this one and wouldn't have if I had known it was missing parts.

Have you got any model filler? regular Hombrol, Revell or Squadron types? use that on the balsa and sand that shiney smooth. Or shape it out of Milliput.
Don't give up yet

I have, and use, lots of balsa and so have a few jars of balsa fillercoat and of clear dope.

Yes Fred I have some Tamiya putty. Perhaps a thin skin of that sanded smooth and then try my luck. Either that or hunt down the Pantera boxing in my stash and try to make a Sculpy male out of it, if it hasn't gotten all hard and useless by now. Failing that I will take up John's advice and see if I can scare up some of the stuff he suggested. If I weren't puttering away at a pair of dead easy S-Model tanks I would put all this stuff away for a while.

Sorry to be late to the party - I have only just seen this. I regularly make moulds from balsa, including clear parts. I used to use A. Hall's talcum powder and dope mixture but have found from experience that this is not necessary. Provided that your mould surface is very smooth you do not have to put any filler on at all - just use the plain wood.

I use balsa sanding sealer . It is dope with a fine powder (talc) as David stated. The purpose is the talc fills tiny wood grain that repeated grades of paper can not get rid of. I have also used body putty with success. But I am old school so stay with the former.

Cheers, thanks.