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Discussion Starter · #1 ·
Hi all,
In the past 2 years I've refinished 12 maple doors that had 45 years of paint on them. (strip, stain & poly)
I also refinished a dozen old desks & chairs. ALL of which came out BEAUTIFUL.

PROBLEM:
I just ran into my first nightmare.
I had a 10 year old oak 4' round table that had a lot of rings, stains, etc..
So I decided to sand the top coat and apply a fresh coat of polyurethane(high gloss)

1 hour after I sprayed the table, I noticed that the polyurethane started to split or wrinkle in some areas. So I removed everything with a chemical. I then lightly sanded, applied AFTER WASH, to remove & clean the chemical residue.

I then stained the table and when it was dry, I sprayed the high gloss poly. When I looked at it an hour later, the god dam wrinkles where back!
My wife is going to KILL me! Please can someone help?
Thanks,
Lou
 

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I bet that it has the older sanding sealer, or, a lacquer primer on it. Poly, I know hates the sanding sealer, and I have seen the lacquer can be a issue? Bottom line, you have a issue, weather a OIL finish, like tung oil, or a old build up of Murphy's oil soap?? Just my 2 cents here!
 

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Dave in Pa said:
I bet that it has the older sanding sealer, or, a lacquer primer on it. Poly, I know hates the sanding sealer, and I have seen the lacquer can be a issue? Bottom line, you have a issue, weather a OIL finish, like tung oil, or a old build up of Murphy's oil soap?? Just my 2 cents here!

Sanding sealer hates Poly?

Please elaborate, Dave.

As I know sanding sealers, they are compatible with every finish.

To the OP:

Sounds like a contamination issue to me.

If that top has sustained years of Pledge or the other brand, ( that has escaped me ) that top is loaded with silicone, which does not bond with any finish.

This is just a stab in the dark, though.

- Scott
 

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Either it isn't urethane or it's contaminated urethane. Try this:

Scuff sand
2 light coats shellac
put on your urethane.


Spray cans of urethane have an unusual solvent mix - I haven't tried this with spray can urethane. You'd only have to do a quick compatibility check on some scrap to see if it plays well with shellac if you're using spray cans..

Depending on conditions, you'll get the 2 coats of shellac on and ready to be top coated in 1-2 hours.

Or you can try to figure out what's going on with the existing finish. If shellac won't stick to it, you won't get anything to stick to it.
 

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Either it isn't urethane or it's contaminated urethane. Try this:

Scuff sand
2 light coats shellac
put on your urethane.


Spray cans of urethane have an unusual solvent mix - I haven't tried this with spray can urethane. You'd only have to do a quick compatibility check on some scrap to see if it plays well with shellac if you're using spray cans..

Depending on conditions, you'll get the 2 coats of shellac on and ready to be top coated in 1-2 hours.

Or you can try to figure out what's going on with the existing finish. If shellac won't stick to it, you won't get anything to stick to it.
Best advice I've read in this thread.

At this point, I'd strip it back of with lacquer thinner & start over. Either use sanding sealer or shellac for 1-2 coats, then 2 coats of poly.

As already mentioned, either your poly is no good, or you've got wax or silicone contamination your battling.
 

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FWIW, some antiques had the grain filled with colored wax, then it had shellac put on. I've filled grain on antique finish repairs this way.
 

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Discussion Starter · #10 ·
THANKS everyone for your replies:
To answer a few posts, YES she was a BIG user of OLD ENGLISH OIL.
But how could old English penetrate through a sealed table? The table seemed to have 10 coats of some sort of a finish.

Ok, so I am going to "assume" that in the wood is some sort of sealer that is screwing up my finish. Do you know what can be applied into the wood (after I remove the stain & poly again) that can remove any oils or sealers?

Boy the last thing I want is to strip it ALL down again, and then have it wrinkle AGAIN. I want to be 100% sure the next method I apply, will solve my issue. Otherwise, I will be forced to bring it to a refinisher and pay more than the table is worth. (not to mention a really PISSED off wife)
 

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Ok, so I am going to "assume" that in the wood is some sort of sealer that is screwing up my finish. Do you know what can be applied into the wood (after I remove the stain & poly again) that can remove any oils or sealers?
Exactly what poly product are you using? How are you applying it?

What stain? Did you make sure the urethane stain you're using is compatible with the urethane finish?

Oils can't be guaranteed to be gotten out of wood in a reasonable amount of time, but doing some acetone wipes with cheap paper towels or clean rags will get most off the surface. Slop it on, wipe it around, wipe it off. For a sealer, you're probably looking at any of the solvent strippers - they'll also take out some oil, so the sequence would be solvent stripper followed by acetone wipe downs.

Keep in mind the oak grain is still going to have junk in it after stripping - it almost never all comes out. So, you still have an unknown surface situation, which means the safest thing to do is do all your prep, then spray (literally spray can) 2 coats of shellac on it.

Since this had rings and stains, it was either heavily worn or it probably was lacquered. With the original finish being gone, there isn't an easy way to tell.
 

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Some of the spray poly have carriers and you have to read the can carefully, recoating at the wrong time will cause the finish to wrinkle. Sometimes need to recoat before 1 hr or after 48 hrs. The silicone contamination I have seen just usually causes very severe fish eyes.
 

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Try a good scrubbing with lacquer thinner after the sanding.And then sand again.Then a scrubbing with laquer thinner.
 

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Sanding sealer hates Poly?

Please elaborate, Dave.

As I know sanding sealers, they are compatible with every finish.

To the OP:

Sounds like a contamination issue to me.

If that top has sustained years of Pledge or the other brand, ( that has escaped me ) that top is loaded with silicone, which does not bond with any finish.

This is just a stab in the dark, though.

- Scott
Most sanding sealers are not compatible with polyurethanes. I wouldn't use anything under polyurethane.
 

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Most sanding sealers are not compatible with polyurethanes. I wouldn't use anything under polyurethane.
I've been using nitroceluous sanding sealer under poly for years & have yet to have finish failure as a result.
 

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Most sanding sealers are not compatible with polyurethanes. I wouldn't use anything under polyurethane.
Ignoring the low VOC waterborne kind of urethanes, there are urethane sanding sealers that are basically thinned urethane, and shellac sanding sealers, and both of those work with urethane.

With the new formulations, I go with whatever the manufacturer says.
 
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