Does anyone know if you can put polyurethane over Formby's tung oil finish? I like the tung oil finish but don't know if is waterproof enough?

Tung Oil is not made for outdoor furniture but it works great on hunting bows that get wet once in a while. Never tried to put poly over it but I'd bet it would work. Try it on a scrap piece first.

Hi Tim.. I was wondering that same thing..I asked around too as I thought the poly might crack or not take well to the bending..from the feedback I have got from other builders on here a polymerize tung oil (lee valley tools has a great poymerized tung oil product 2 in 1 type..used it on other carvings and it is excellent) works well for bows too..

Tim, I use a tung oil based varnish over a pure tung oil dip on bamboo rods. The product is made by Sutherland Wells and is fantastic.  I would not trust the bond of the poly over the oil.

I used  Tung Oil for the first time and could never get the flow and finish I liked. Scuffed it off and put 3 coats of polly over the tung oil for a beautifull job.

Guess tung oil works the same way as a primer for following coats of poly ar acrylic than linen oil does.

The formby's "tung oil" is not tung oil.  Get some 100% tung oil and it will be VERY waterproof after about 5 coats.  I would sand the formby's all the way off.  It is soft, shiny, and does not repel water.  I think it is desgined for hand rails and bannisters.  Wood crafter carries and excellent 100% tung oil.  I have a 12 ounce bottle, have done more than a dozen bows, and still have most of it left.  Just remeber to push ALL of the air out of the bottle between openings

Thanks for all the replies.This was my first attempt at an osage bow and was so exited that it tillered out, and made weight that I could'nt wait to get a finish on it. It turned out to be a  great, looking,and shooting bow.
I kinda jumped the gun.I Should have researched first acted second. I'll probably leave this one as is. I'll know better next bow.