Has anyone tried to use a spray on fast drying polyurethane for a pre treatment to covering with monokote verses balsarite?

Why do you apply anything to the wood when covering with Monokote? Nothing should be used on the wood. Balsarite is only intended to be applied to the framework when the covering material does not have an adhesive layer, such as on Micafilm.

Actually, when Balsarite first came out it was advertised as helping all iron-on coverings stay down better, etc. I tried it once and it didn't do anything good for me except take more time and cost more money.

And I agree that the wood should not be sealed prior to putting on monokote.

Ditto. Don't know about the poly idea but anything except a very cool iron will give you fits when covering over Balsarite.

If you thin the Balsarite about 50/50 with Ironex and brush on a couple of thin coats, then sand lightly, it really helps make a more permanent, smooth bond. If you have trouble with it, you've got too much on. Having said all that, using the Balsarite under Monokote is kinda over-doing it, and I rarely bother.

I have read someplace that you can use hair spray to make monokote stick better, is this true?

Tanks for the replies. I get the feeling that I have just fallen for a advertising gimmick! What exactly was Balsa-rite good for?

> What exactly was Balsa-rite good for? <

I explained this in my first reply to your question. It is also useful for fuelproofing a fuel tank compartment using two heavy coats. And it can be used to deal with troublesome edges of covering that lift off. Clean the loose edge, apply a little Balsarite, and it can be stuck down again.