What's happened to my padauk?

[Joe Unni]

Hey all,

I'm finally getting down to the finishing portion of this long and drawn out project. It seems that the padauk top (or the underside as seen below) is absorbing finish (Generals Oil/Poly) in a peculiar way. Part of the top is nice and shiny while the other seems much more dull. It happens right on a joint line. My guess is that the boards used for the dull section of the table are of a different tree or type of paduak - I really don't know. My fear is that when I flip it and begin to finish the top side, the same phenomenom will happen. What can I do, if anything, to remedy this?

You can kind of see it here.
63199
Here it's glaring (or not) right at you!
63200

Thanks in advance,
-joe

[Joel Ficke]

I would think a thin coat of shellac before oil/poly would help with this. Give it a try on some scrap from the offending board and see what happens.

[Ken Werner]

Joe, That is strange. Could the wood have been burnished or coated in some way? The shellac makes sense to me, but I wonder if you should sand the entire surface down to bare first.
Ken

[glenn bradley]

That almost looks like the boards went through a different sanding protocol before they were glued up. I assume there was sanding or scraping after the glue up that would have eliminated this.

If this is just different tree behavior then I would agree that a sealer may homogenize the surface. I'll be anxious to see your progress.

[Terry Bigelow]

I'm with Glen, try to seal first then sand with 220 and maybe even a second sealer before you sart with the top coat.

[Joe Unni]

I would think a thin coat of shellac before oil/poly would help with this. Give it a try on some scrap from the offending board and see what happens.

I will. Are you suggesting seal and then a test top coat?


Joe, That is strange. Could the wood have been burnished or coated in some way?

Nope. Purchased rough, all the boards where jointed and planed at the same time.


That almost looks like the boards went through a different sanding protocol before they were glued up. I assume there was sanding or scraping after the glue up that would have eliminated this.

If this is just different tree behavior then I would agree that a sealer may homogenize the surface. I'll be anxious to see your progress.

Once glued. Planing, scraping and sanding took place on the entire glue up.


I will say that I noticed two things during this process.
1. the offending lighter boards worked differently (i.e. more easily) during the planing and scraping process.
2. while applying the finish they seemed to absorb the finish more rapidly to where I had to tip off my rag much quicker so as not to get any friction marks.

Well I'll try to seal and we'll see what happens.

I'll keep you all posted.

Thanks,
-joe

[Howard Acheson]

I'm curious, how many coats did you apply? How did you apply them?

[Joe Unni]

I'm curious, how many coats did you apply? How did you apply them?

I wiped on about 5 or 6 coats.

[Joel Ficke]

Joe,

Something similar happens to me with mahogany sometimes -- it's almost like the density or porosity of the wood varies from tree to tree. More open grains => more absorption of the oil.

If you apply a thin (1#) coat of shellac, then sand the surface lightly (or even rub it well with a fine scotchbrite pad), then apply your finish as before you should get better results. It still won't be perfectly uniform, but I'm guessing it will be better than you have now. The shellac will more or less coat the internal pore area and prevent further absorption. Give it a try on some cutoffs from each board and see if things change before trying it for real.

-joel