I've used u40 on the cork grips I've made. My question is for birch bark with cork accents on both ends, can I use u40 or should I go to tru oil?

Based on my experience with both on cork, I think it will depend on whether you want to retain original color or have it darken and get more contrasty. Tru-Oil will do the latter more than U40.

Since Tru-Oil by itself is a good gunstock treatment I would choose it for birch to have the most confidence in long life preservation of the grip. Probably multiple VERY light coats. When I use it on gunstocks I just put a few drops in my hand and rub it on and in well. I don't build up any significant "layer" with each application.

Tim,
I tend to agree with Michael although have limited experience. The two birch bark handles I have made thus far employed cork as well, the first with U40 Cork Seal and the second with Tru Oil. I have relied upon U40 for all my cork in the past, hence using it on the first birch grip and everything appears to be fine. Since the almost unanimous consciences is to use Tru Oil on birch bark handles, I used it on the second grip and actually like it better. I have not had the opportunity to test the Tru Oil in a real-world fishing environment but the overwhelming majority can’t be wrong.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

Being more of an actual wood than cork is, I'd recommend some type of actual finish on the birch bark. Either PermaGloss or Tru-Oil will work well.

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I was leaning to the tru oil as I have been researching these posts. My concern was, will the cork take the tru oil. Not looking for a real glossy finish just a little sheen.

The TO will produce a sheen similar to U40 CS.

Mark Talmo
FISHING IS NOT AN ESCAPE FROM LIFE BUT RATHER A DEEPER IMMERSION INTO IT!!! BUILDING YOUR OWN SIMPLY ENHANCES THE EXPERIENCE.

If in doubt, try a little on a few cork rings and see if it does what you want. Don't put on enough to build up a coat. Hand rub it. It will not get glossy. The biggest change will come with burl cork because it will affect the glue that holds the stuff together more than the cork itself. It gets a darker and shows a lot of contrast between the cork pieces and the glue. The glue "takes" the TO more than the cork.

I typically go for a gloss finish but if customers just want a light sheen, three will do it. I also steel wool (0000 size) the grip after each coat as TO will rise wood fiber a little. Five coats lasted me five years on a heavily used freshwater spinning rod and all I did was a light sanding andtwo more coats of TO. No filled pits ever fall out with TO.

Ray Zarychta
Glastonbury, CT

Cork will not accept any thing , it will only go on top of the cork , if I remember correctly ,

William Sidney
AK

Yes, cork is a closed cell structure, so it does not absorb, however a top coating like U40 cork seal or Tru-Oil will provide a long lasting finish. The color effects of each are different. Test if you are not sure.