What finish material does Eastman's "Open Pore" finish use?

[Wade Hampton]

I was reading the spec sheet on a guitar made by the Chinese violin, mandolin and guitar company Eastman, and when I got to the line about its finish it read: "Open Pore." It's a satin finish on the guitar, I know that, having played one. But is it polyester based? Do any of you know, or know of someone I can ask?


Wade Hampton Miller

[tomcstokes59]

You could email their contact address. Eastman CS is usually very responsive.

https://www.eastmanguitars.com/contact

[Wade Hampton]

Thanks, Tom, I just did.


Wade

[robj144]

Originally Posted by Wade Hampton

Thanks, Tom, I just did.


Wade

Let us know. I have it on my electric Eastman. I always thought it was a French polish-like finish.

[zombywoof]

May just be a matter of using no grain filler.

[charles Tauber]

Originally Posted by zombywoof

May just be a matter of using no grain filler.

That's the definition of an "open-pore" finish, that the "grain" (pores) of the wood were not filled as part of the finishing process.

Note that only "open-pored" woods "need" filling. "Closed-pore" woods, such as spruce, cedar, maple, poplar, birch... have pores small enough to not require filling in order to achieve a smooth finished surface.

[Silly Moustache]

Looks like creosote to me ...but nice!

[zombywoof]

Originally Posted by charles Tauber

That's the definition of an "open-pore" finish, that the "grain" (pores) of the wood were not filled as part of the finishing process.

Note that only "open-pored" woods "need" filling. "Closed-pore" woods, such as spruce, cedar, maple, poplar, birch... have pores small enough to not require filling in order to achieve a smooth finished surface.

Obviously the only wood that would be grain filled is that used for the back and rim such as rosewood. Unless it is an all-mahogany guitar, there is no reason to apply the technique to the finish of the top.

[jklotz]

Originally Posted by Wade Hampton

Thanks, Tom, I just did.


Wade

Wade, please report back once you get an answer. I'll be interested to know what they say. Thanks.

[Wade Hampton]

Will do.


whm

[charles Tauber]

Originally Posted by zombywoof

Obviously the only wood that would be grain filled is that used for the back and rim such as rosewood.

And the neck, bindings or head veneer, or any other part for which a smooth finish is desired when using an open-pored wood.

Unless it is an all-mahogany guitar, there is no reason to apply the technique to the finish of the top.

Koa is sometimes used for tops and usually requires pore-filling, if one wants a smooth surface. For conifers, which are generally close-pored woods, you are right, no filler is required.

[Pura Vida]

Originally Posted by robj144

Let us know. I have it on my electric Eastman. I always thought it was a French polish-like finish.

The varnish finish on some Eastman electric and acoustic models (designated with the "v" in the model number) is different than the open pore finishes that they're using in some of their more affordable acoustic guitar models. I'm not aware of any open pore finishes in their electric guitar line.

[Wade Hampton]

Okay, I just spoke with Dan in Eastman’s Pomona, California office. According to the gentleman who answered their telephone Dan is their designated “guitar guy,” and the person to ask when any questions about their guitars arise.

Dan told me that their “Open Pore” finish is a satin nitrocellulose lacquer finish. I have owned some instruments finished in satin nitrocellulose, mostly mountain dulcimers, and know that it’s nice and light and doesn’t inhibit the sound in any way. However, it’s also easily rubbed through or at least accidentally burnished into a semi-gloss in spots where it receives physical contact from the player.

When Dan told me that the “Open Pore” finish was nitrocellulose lacquer I was surprised, but then realized that I shouldn’t be, since Eastman already uses a high gloss nitro finish on other guitars built in the same factory. Eastman’s “Open Pore” finish guitars would go through the same finish room and be sprayed with the same nitrocellulose lacquer with the same equipment, the only difference being that they probably only receive a base coat instead of the multiple coats necessary for a high gloss finish.

Anyway, since these guitars are finished in nitrocellulose, the same rules apply: avoid vinyl entirely, since when vinyl comes into direct contact with nitro there’s a nasty chemical reaction. Guitar polish should be avoided, as well, since there isn’t enough finish material on there to shine up, and if shined up there’s a very real danger of completely blowing through the finish and reaching the bare wood underneath.


Wade Hampton Miller

[tomcstokes59]

Thanks Wade for the follow up and post.

[docwatsonfan]

Thanks Wade for the info

very cool to know!

I'll have to stop wearing my vinyl t-shirts