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Help with Poly on brazilian cherry valet

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Forum topic by OldBull posted 01-24-2022 06:37 PM 480 views 0 times favorited 19 replies Add to Favorites Watch
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OldBull

570 posts in 754 days


01-24-2022 06:37 PM

Good afternoon on a chilly Florida day,

I made a brazilian cherry valet for my nephew. He is a very hard worker (and has a lot to show for it) and according to his wife he has many items such as small tools, keys, knives, coins etc. come out of his pockets at night. The toughest finish I have read about is oil based polyurethane. Brazilian cherry I believe can blotch and the “you can/you can’t” poly over shellac argument seems to be never ending, So I am a little skeptical of shellac under poly.

The only poly I have used was wipeon poly just to protect a pine utility box in my 4runner. I have some minwax pre-stain on hand but did not know if that could be used under oil based poly. Truth be told, I don’t even know that brazilian cherry will blotch at all or with poly.

What is your suggestion for a tough finsh on a valet? If it is oil based poly, what is your suggested undercoat?

Thanks for any help.
Donny


19 replies so far

View Lazyman's profile

Lazyman

9601 posts in 2846 days


#1 posted 01-25-2022 04:09 AM

I have heard people say shellac under poly works for them and others say it they had problems with it so I have never tried it. Personally, I don’t think it is necessary anyway.

Best way to find out if it will blotch is to test your finish on a scrap piece. Not sure there is really any way to avoid blotching on woods like cherry that are prone to blotching. Most of the products out there are really for preventing blotching with stains. If I was worried about it I would probably start with DIY wiping poly by mixing mineral spirits with oil based poly. Start with a very diluted mix like 2 parts MS and 1 part poly or even weaker and after applying a several coats switch to the full strength for the last couple of coats. You could also gradually increase the strength during the first few wipe-on coats before switching to full strength. But test it first on scraps, regardless.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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Rich

8120 posts in 2048 days


#2 posted 01-25-2022 04:41 AM

De-waxed shellac is a versatile go-between finish. It’s OK to use over virtually any finish and under virtually any topcoat—and most definitely can be applied under varnish. Polyurethane is a varnish. However, the question of whether you should use shellac in your application is a different issue.

You’re concerned about blotching, but you don’t say that you plan to apply stain or dye. If you’re going to simply go with a clear topcoat, you don’t need to worry about blotching. If you do plan to use stain or dye, let us know.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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SMP

5311 posts in 1364 days


#3 posted 01-25-2022 04:48 AM

Yep, as Rich mentions, unwaxed shellac will work under it just fine on virtually anything. People that say you can’t probably didn’t buy dewaxed shellac, or assumed it was incorrectly. But personally I would just put some Arm r Seal on it and call it a day. One thing on cherry if there are quarter sawn pieces you can get those splotches that take topcoat differently and can look blotchy. You can try it on a test piece.

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Peteybadboy

4840 posts in 3408 days


#4 posted 01-25-2022 12:35 PM

I use shellac (tinted) under poly all the time. I use it to pop curly grain. Works great

-- Petey

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OldBull

570 posts in 754 days


#5 posted 01-25-2022 02:05 PM

Thank you Lazyman, Rich, SMP, and Peteyboy, That was exactly the answer I needed. You folks are awesome.

As far as stain I should do domething to darken the cherry. I thought cherry darkened with age but I have been reading that it lightens with age?? One problem is the piece is assembled making finishing a bit tougher. Their bedroom furniture is very dark. I have 1Qt of oil based GF georgian cherry and a small can of GF oil based black, both are gel and I have never used gel before. I have amber flakes but also have appx 1qt of blonde 1.5lb cut already mixed from december. Maybe I could mix the georgian cherry and black together ??? One problem with Gel is I went all the way down to 400 grit for feel.

If I am making it darker maybe blotching is not a factor.

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Rich

8120 posts in 2048 days


#6 posted 01-25-2022 02:18 PM

There’s a lot going on here. You’re using Brazilian cherry, AKA Jatoba. According to the Wood Database, it does darken from exposure to light. It also might, or might not, blotch like domestic cherry. I’ve never worked with it, so I can’t say. It is gorgeous wood though and might be a good candidate for finishing with a topcoat alone.

If you compare it to domestic cherry, you’ll see that it has completely different properties.

Take Nathan’s advice and do test boards.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

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OldBull

570 posts in 754 days


#7 posted 01-25-2022 02:23 PM

What is your feeling on rattlecan polyurethane ?? The pic here is before final sanding, I had some uneven edges to deal with still.

”” It is gorgeous wood though”” Pain in the butt wood, it was under tension and took forever to get flat.
.
.
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View CL810's profile

CL810

4298 posts in 4447 days


#8 posted 01-25-2022 03:04 PM

Two things to do to reduce blotching: 1) Sand to 400 or 600 grit. 2) Use a thinned de-waxed shellac a as seal coat. Have you tested any of your ideas to see if they are causing blotching?

-- "The only limits to our realization of tomorrow will be our doubts of today." - FDR

View Lazyman's profile

Lazyman

9601 posts in 2846 days


#9 posted 01-25-2022 03:09 PM

You could actually try putting a scrap in a sunny window for a few days to see if it darkens any. Direct sunlight will sometimes darken woods prone to darkening within a few hours, though I do not have any experience with Brazilian cherry to know if it is one that will turn that quickly or how much it may darken. If the scrap darkens and you like the effect, you could put the box there and rotate it frequently so that all sides get exposed.

Personally, I would not try to match the other wood colors in their room. I like to see some contrast, especially a small item, so that it doesn’t just blend in and become invisible. But that is just a person preference.

BTW, if you do decide to apply some stain and through testing think that blotching is going to be a problem, you can make your own glue/finish sizing to help reduce the effect. The Wood Whisperer had a video recently on a DIY blotch control that actually seemed to work pretty well on some splotch prone pine he used to demonstrate how effective it is. I have not tried it and YMMV so again, test it on some scraps.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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OldBull

570 posts in 754 days


#10 posted 01-25-2022 03:31 PM

Have you ever used rattlecan poly ??? No test yet, weather here has been rain then cold then warm and repeat, so I have held off while I ask the community for advice. I will take a scrap piece and play around.

View Madmark2's profile

Madmark2

3439 posts in 2047 days


#11 posted 01-25-2022 03:40 PM

I use a lot of jatoba and never had splotches. It takes poly well. I wouldn’t try to stain it. Fresh off the saw it can be orangish-red but quickly starts to darken. Eventually it turns a rich burgundy.

Minwax semi gloss oil based poly applied with a foam brush. 2 coats 50%-50% Poly/MS mix, 3rd coat full strength.

-- The hump with the stump and the pump!

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OldBull

570 posts in 754 days


#12 posted 01-25-2022 03:49 PM

Hellllllloooo @Madmark2, where ya been hidin ? Thanks, still looking to see if anyone has used rattlecan ???

P.S. orangish red with a little green !!

View HokieKen's profile

HokieKen

21709 posts in 2597 days


#13 posted 01-25-2022 04:52 PM

Are you sure that’s Jatoba? It sure looks like domestic Cherry to me in that photo. Any Jatoba I’ve used has a different color and grain from what I see in your photo. MadMark’s photo is what I’m used to seeing.

-- I collect hobbies. There is no sense in limiting yourself (Don W) - - - - - - - - Kenny in SW VA

View Lazyman's profile

Lazyman

9601 posts in 2846 days


#14 posted 01-25-2022 05:11 PM

Now that you mention it, that does look like black Cherry.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

View SMP's profile

SMP

5311 posts in 1364 days


#15 posted 01-25-2022 05:31 PM



Are you sure that s Jatoba? It sure looks like domestic Cherry to me in that photo. Any Jatoba I ve used has a different color and grain from what I see in your photo. MadMark s photo is what I m used to seeing.

- HokieKen

Maybe its from Brazil, Indiana?

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