finish not setting up

[jeffp51]

I have added tip overlays to my latest bow made of african black wood.  My normal tung oil finish never really set up on it, so I sanded that off and tried spray on polyurethane.  that seems a little better, but after 3 days it is still a little tacky--more like soft.  I prepped the surface with acetone, but it hasn't seemed to help.  any ideas why, or what to do now?  I suspect the wood is pretty oily, but that didn't affect the glue up, so I am at a loss right now.

[bradsmith2010]

well if its oily,, sand off finish,, clean with soap,, then spray, and put in a room with higher temp,,,, it should work,,

maybe several thin coats

[Pat B]

If the weather is wet some finishes seem to take a while to set up or maybe the tung oil is old or it's too cold. I've never used tung oil but these conditions have had that affect on finishes I've used.

[artcher1]

You might try coating the tips with thin super glue first, then finish. Or use the super glue as your final finish. Saturate a Q-tip and rub in. Sand between coats using #0000 steel wool...…..Art

[Bubbabowyer]

I use osage and it seems to like tung oil better when it's been warmed up a bit. 130 degrees or so for some time. I apply very thin coats twice whilst the bow is warm and then set it on the shelf for a week then give it another good coat and immediately wipe down with a linen handkerchief. Seems to work well.

[bownarra]

No it is none of those reasons -  it is the oils stopping the finish drying. I guess most people don't have much experience with the more 'exotic' woods. To get the finish (any finish) to dry properly first you need to add a few coats of shellac. This will set 100% guaranteed regardless of wood species. You can then add your tung oil finish or whatever over the top of the shellac. Simple
And rubbing with acetone will make the problem worse. Acetone will help remove some surface oil but it draws more up from inside the wood. Do not use acetone to degrease any wood, it doesn't work and is likely to make the situation worse.
Good luck

[Badger]

No it is none of those reasons -  it is the oils stopping the finish drying. I guess most people don't have much experience with the more 'exotic' woods. To get the finish (any finish) to dry properly first you need to add a few coats of shellac. This will set 100% guaranteed regardless of wood species. You can then add your tung oil finish or whatever over the top of the shellac. Simple
And rubbing with acetone will make the problem worse. Acetone will help remove some surface oil but it draws more up from inside the wood. Do not use acetone to degrease any wood, it doesn't work and is likely to make the situation worse.
Good luck

  Exactly what I was going to say, modern bowyers have been dealing with this for years on their exotic wood risers.

[Flntknp17]

No it is none of those reasons -  it is the oils stopping the finish drying. I guess most people don't have much experience with the more 'exotic' woods. To get the finish (any finish) to dry properly first you need to add a few coats of shellac. This will set 100% guaranteed regardless of wood species. You can then add your tung oil finish or whatever over the top of the shellac. Simple
And rubbing with acetone will make the problem worse. Acetone will help remove some surface oil but it draws more up from inside the wood. Do not use acetone to degrease any wood, it doesn't work and is likely to make the situation worse.
Good luck

What solvent should be used then instead of acetone?  I’ve been using it for many years before gluing bamboo backs and also on tips and handles.  If there is something better I’d switch. 

Thanks

Matt

[High-Desert]

Acetone works fine to degrease wood, from my experience, but the exotics are extremely oily, so like the others have said, a few light coats of shellac on your exotics works fine, no reason to try to decrease them. “Everything sticks to shellac and shellac sticks to everything” I think the saying goes.

[PatM]

Acetone is fine for degreasing.  Just do it a couple of times.  The thought that it immediately draws oils back to the surface is silly.    It takes time for that to happen.  You get your glue or finish on before that happens.

[JW_Halverson]

What's wrong with using a straight up shellac finish? I have been using it for years and I am really pleased with the results. If you do not want the shiny finish, build up 6-8 layers and give it a very light going over with 0000 steel wool.

Shellac seals nicely and resists rain rather nicely.

[jeffp51]

The shellac I have is not a very hard finish. It scratches easily.  How do you get around that?

[PatM]

Use a better finish.