# What about finishing exotic woods?



## Mike (Nov 22, 2004)

It is often difficult to find an answer on finishing exotic woods so I asked Michael Dresdner for any suggested reading or tips.

Q: Have you published anything on finishing exotic woods?
A: I have published four books on finishing. All deal with exotic wood to some degree, but the truth is that with very few exceptions, finishing exotic wood is no different than finishing domestic wood. The notable exceptions are those woods that belong to the genus dalbergia. These include all the true rosewoods, cocobolo, kingwood, African blackwood, and a few others. The only problem with these woods is that they contain an antioxidant that will prevent curing of any finish that uses oxygen polymerization. Among small shop and hobby woodworkers, that includes all oil based finishes; on the industrial side, it includes polyester and UV cured coatings. 

To get around the problem, simply seal the wood first with Zinsser SealCoat after which any common coating will cure over it. With polyester and UV coatings, vendors typically offer a cross linking sealer specifically paired to their coating. 

Michael Dresdner


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## curiousgeorge (Nov 6, 2006)

Thanks Mike. Very informative.


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## Joe Lyddon (Sep 11, 2004)

Mike said:


> To get around the problem, simply seal the wood first with *Zinsser SealCoat* after which any common coating will cure over it. With polyester and UV coatings, vendors typically offer a cross linking sealer specifically paired to their coating.
> 
> Michael Dresdner


Mike,

Is that Zinseer SealCoat the same as a 1# cut of shellac?
If not, would shellac seal it also?


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## challagan (Feb 7, 2006)

Thanks Mike, I know several box makers and wood turners that use acetone wash on these woods prior to finishing. I have used it for several pens I made in cocobolo and Kingwood. I will have to pick up some of the seal coat. 

Corey


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## bobj3 (Jan 17, 2006)

Finishing tips and more info about shellac & Zinseer

http://www.woodcentral.com/cgi-bin/readarticle.pl?dir=finishing&file=articles_309.shtml

http://www.newparks.com/parksclear-pg.html

http://www.woodfinishingsupplies.com/shellac_l.htm

Bj


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## Mike (Nov 22, 2004)

Joe, shellac will stick to peanut butter, or at least so the saying goes. Is the Zinseer SealCoat the same as a 1 lb. cut of shellac? No, Zinseer has a forumla to help keep the solution mixed in the can. Since Michael mentioned this product specificly that would be my choice.
Corey, I learned from Michael that washing with acetone prior to finishing is counter productive, it actually causes more of the oil inside the wood to weep than simply fine sanding. This wash method was used on teak and I have heard other experts suggest it. Washing other woods is a complete waste of time, there is no benefit.


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## Joe Lyddon (Sep 11, 2004)

Mike said:


> Joe, shellac will stick to peanut butter, or at least so the saying goes. Is the Zinseer SealCoat the same as a 1 lb. cut of shellac? No, Zinseer has a forumla to help keep the solution mixed in the can. Since Michael mentioned this product specificly that would be my choice.
> Corey, I learned from Michael that washing with acetone prior to finishing is counter productive, it actually causes more of the oil inside the wood to weep than simply fine sanding. This wash method was used on teak and I have heard other experts suggest it. Washing other woods is a complete waste of time, there is no benefit.


It seems like I've seen Norm wipe down many exotics before glue-up *as well as* Finishing. Maybe he's doing it for finishing out of habit... ... before glue-up to make the joints glue better?


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## Mike (Nov 22, 2004)

Yes Joe, Norm uses the wash to remove the oil before applying glue or finish on teak. Michael Dresdner recommends to not follow this process. Since he is the one with the education in chemistry and finishing I take his word for it.


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## Joe Lyddon (Sep 11, 2004)

Joe Lyddon said:


> Mike,
> 
> Is that Zinseer SealCoat the same as a 1# cut of shellac?
> If not, would shellac seal it also?



OOps... 2# cut...   :sold: 
http://www.woodfinishingsupplies.com/shellac_l.htm


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## challagan (Feb 7, 2006)

I have used acetone for some pens in the past, I didn't have any problem with the few I did it on but probably just luck. My main pen finish is a waterborne 2 part poly finish that has a seal coat first and then a gloss top coat. In the past I have used lacquer for my boxes using oily woods but I would prefer to use my wipe on poly mix for most boxes (Ntiro cell lacquer will kill yah) ... unless I want a real clear finish. I will have to pick up some Zin and give it a try. 

Corey


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