Joe, I do NOT recommend Mod Podge.  I used it on Endgame, and I am disappointed. It has a super adhesive quality, in my opinion better than Balsarite but it has some negatives that I was not expecting.  It has bubbled up in several places under the monokote and given the appearance of sharkskin. It may be that it needed to dry longer, or I waited too long.  Don't know.  I put on two coats a day apart and sanded glass smooth before applying the Monokote.  Crist is the one you need get with.  His planes look first class.  I think he puts it directly on the raw balsa.

I have also used Poly Crylic.  It helped fill the grain but not much on the adhesion.  My best results on wings have been raw balsa, lots of heat with a gun and rubbing with a cotton cloth while it is still too hot to touch.  Good luck, hope to see you at the field soon!

Ken

I use Mod-Podge straight from the jar.  Brush it with the chip brushes from HF.  Let it dry and I do not sand it.  I also put doc paper on before the Monokote and have good results.  On open bays do not seal the doc paper.   

I have had very good results by sanding smooth the wood with 400 grit sandpaper, cleaning off with a tag rag then applying one coat of Balsarite for Film to the wood. This soaks in, sand lightly with 400 grit sandpaper, clean off with tag rag and apply film with low heat. Be careful to get the film on smooth as once it is on with this approach you will not be able to pull it up without separating the color from the top sheet.

Best,   DennisT

If you look at my planes you will see filets as such.  I put a strip of MonoKote in the joints.

In case anyone is interested, I have tried this product when I use an iron-on covering. Seems to work well so far. I did see it on a few hobby shop web sites, however, all out of stock. I did find it on eBay.

Thanks to all who responded.  I appreciate your comments.

Joe