Wipe-on Poly on Bocote

[Kevin Weir]

I’m making another run of goblets. One of the woods is Bocote. But I have no experience with using wipe-on poly on Bocote. There are other woods such as padauk that tend inhibit the drying of wipe-on poly, possibly due to the oils in the wood. Have also had a similar experience with African Blackwood too. So two questions: does anyone know how to prevent the inhibition of drying on these woods? And will the Bocote react the same way? It seems a bit on the oily side to me. Also, I’m turning a new wood called Rengas. Has anyone turned this?

 

[Tim Connell]

One way is to wipe them down immediately before finishing with a liberal amount of acetone to remove the surface oils.

Another way is to apply a barrier coat of shellac to seal the wood before the poly is applied.

 

[Tom Gall]

Tim has it right. Especially the shellac sealer coat.

 

[Kevin Weir]

That makes sense. Will give the acetone a try. Thanks Tim.

 

[Mark Jundanian]

With oily exotics sometimes leaving the wood bare is an option. I did this with a cocobolo piece I made last year.

 

[John Kennedy]

No experience with the specific woods, but the solvent wipedown and sealant is the way to go. Have experimented over the years with wipe on poly (always looking for a cheap DIY home made formula)
In short, wipe on poly is just diluted poly. Way more expensive than straight poly per the amount of resin in a can. Good analogy is like the 50/50 car coolant that charges you excess for adding half water so you don't have to dilute it yourself.

Products like Minwax don't advise diluting the stuff but that's because they can't assure a viable result. Not because you can't do it and still get a beautiful finish.

You can make your own by diluting one part poly with 2-3 parts mineral spirits. Have used this on wood and rocks. I guess my point is that anything that thins straight polyurethane makes a wipe on product. Going up the chain of aggression with the solvent from mineral spirits to MEK also helps penetrate a bit deeper if there is some oil in the wood.