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Guy Gagnon
Polyurethane finishing
Guy Gagnon

Looking for a not so difficult way to correct a botched up urethane job on a 60 year old red maple table top. I've done many urethaneings back in the day but never have any turned out like this. I initially cleaned the surface with 0000 wool and mineral spirits. After several days I applied a coat of Ipswich Pine red stain which never really dried thoroughly so I rubbed it off after several days. I then proceeded to start the first of three coats of Minwax oil based fast drying satin poly, sanding with 320 in between coats. It looked blotchy after every coat which I applied 24 hours apart. After the final coat I sanded slightly with 100 as per Minwax instructions and I ended up with a scratched, blotched up surface. Would greatly appreciate a solution to this problem. Thank you for your consideration.

A. Spruce
Re: Polyurethane finishing
A. Spruce

The problem is that you used a Minwax finish. Their stains are great, their finishes are complete and utter garbage. You are not going to be able to cover up the bad finish, leaving the only option of sanding it back to bare wood and starting over. When you do start over, choose a different finish, McKloskies is my favorite because it is very very user friendly and produces excellent results.

One word of caution, before you start slathering your project, to a test over some of the old finish to make sure that new and old are compatible, the last thing you want to have to do is sand it down yet again.

ed21
Re: Polyurethane finishing
ed21

I can't believe minwax or anybody would recommend sanding with 100 grit after the final coat. The final coat is usually it. I don't recall ever sanding or even steel wooling after the last coat.
That would make any finish look bad.

Jack
Re: Polyurethane finishing
Jack

I agree with Spruce, Minwax poly is garbage. The fact that the stain did not dry in several days suggests that the stain was bad. Blotchy usually means an uneven absorption of stain. 100 grit is a starting grit for leveling not for finishing. For a stain finish some do recommend lightly buffing with oooo steel wool to remove the luster.

Jack

Sombreuil_mongrel
Re: Polyurethane finishing
Sombreuil_mongrel

When you state in the first sentence that you cleaned the surface with steel wool, what did you do before that? Strip or sand the old finish off? (yes. I hope)
If you mean you cleaned the old finish, then attempted to apply oil stain on top of it, full stop. Liquid oil stain goes on bare wood only, ever.
Then you "rubbed it off" hopefully with lacquer thinner or some solvent, and clean rags.
Was the varnish you resorted to acrylic or oil? Show us on the label where it says to sand any poly with 100 grit after the final coat. Poly is a one-shot: due to the shape of the molecules it can't be rubbed out in any way, with any grit after it has dried without becoming and staying forever hazy.
Casey

ed21
Re: Polyurethane finishing
ed21

So much of what you did doesn't sound right. Stain isn't left on for days, it's usually applied then the excess rubbed off in 10 or 15 minutes. Was it applied to bare wood or over another finish.
Light sanding or steel wool between coats is good, but 100 grit is usually for bare wood before finer sand paper.
I have a can of minwax poly, which I agree is not a very good product, and I checked the instructions and they are nothing like what you stated. It says sand lightly with 220 after the first coat, then nothing for subsequent coats.
You may have mixed up the instructions for the stain with the poly.

Guy Gagnon
Re: Polyurethane finishing
Guy Gagnon
A. Spruce wrote:

The problem is that you used a Minwax finish. Their stains are great, their finishes are complete and utter garbage. You are not going to be able to cover up the bad finish, leaving the only option of sanding it back to bare wood and starting over. When you do start over, choose a different finish, McKloskies is my favorite because it is very very user friendly and produces excellent results.

One word of caution, before you start slathering your project, to a test over some of the old finish to make sure that new and old are compatible, the last thing you want to have to do is sand it down yet again.

Thanks for your response. I think I'm getting too old for this. I seem to have screwed it up royally. Never heard of McKloskies. Who carries it? As far as the job I did. I might try rubbing it over with a good paste wax. Any result I get will be better than what I have. What do you think?

Guy Gagnon
Re: Polyurethane finishing
Guy Gagnon
ed21 wrote:

So much of what you did doesn't sound right. Stain isn't left on for days, it's usually applied then the excess rubbed off in 10 or 15 minutes. Was it applied to bare wood or over another finish.
Light sanding or steel wool between coats is good, but 100 grit is usually for bare wood before finer sand paper.
I have a can of minwax poly, which I agree is not a very good product, and I checked the instructions and they are nothing like what you stated. It says sand lightly with 220 after the first coat, then nothing for subsequent coats.
You may have mixed up the instructions for the stain with the poly.

Thanks for your response. You are so right. I screwed this one up royally. I'm getting too old for this. I just took another look at the instructions which I misread completely, probably because they were so lengthy plus this one gallon can of poly is for doing hardwood floors. Not sure if that makes any difference. I'm now thinking of rubbing it over with a good grade of paste wax. Anything will look better than it is. What do you think?

Guy Gagnon
Re: Polyurethane finishing
Guy Gagnon
Sombreuil_mongrel wrote:

When you state in the first sentence that you cleaned the surface with steel wool, what did you do before that? Strip or sand the old finish off? (yes. I hope)
If you mean you cleaned the old finish, then attempted to apply oil stain on top of it, full stop. Liquid oil stain goes on bare wood only, ever.
Then you "rubbed it off" hopefully with lacquer thinner or some solvent, and clean rags.
Was the varnish you resorted to acrylic or oil? Show us on the label where it says to sand any poly with 100 grit after the final coat. Poly is a one-shot: due to the shape of the molecules it can't be rubbed out in any way, with any grit after it has dried without becoming and staying forever hazy.
Casey

Thanks for your response. Appreciate your help. I screwed this one up royally. I'm getting too old for this. I misread the instructions completely. What I did was clean the surface first with 0000 wool and mineral spirits, then proceeded to apply a coat of stain to fill in the lighter spots (first mistake) then three applications of oil based poly with 0000 sanding between coats and 100 grit after the final coat. What I'm thinking of doing to see if I can improve it's appearance is to rub on a good grade of paste wax. What do you think?

A. Spruce
Re: Polyurethane finishing
A. Spruce
Guy Gagnon wrote:

I just took another look at the instructions which I misread completely, probably because they were so lengthy plus this one gallon can of poly is for doing hardwood floors. Not sure if that makes any difference.

The fact that you used floor finish is of little consequence, as "floor finish" pertains to the hardness and durability of the product.

Guy Gagnon wrote:

I'm now thinking of rubbing it over with a good grade of paste wax. Anything will look better than it is. What do you think?

While this, initially, looks like the easy way out, I strongly urge you NOT to do this, as all you will be doing is creating yet a deeper hole from which to extract yourself from when it fails too.

At the very least, finish sand the surface again with at least a 150 grit paper, by hand, use strokes that are parallel to the grain, DO NOT use a power sander, as you will leave swirlies behind. Once you've got the surface evened out, then apply one last coat of the poly you have been using. DO NOT sand or abuse this final coat in any way! While it may not be perfect, at least it is smooth and intact. With this "fix", should you wish to refinish this table again, you won't have wax in the mix that will seriously turn your experience into a bad day. You think you got fish eye in your finish now, go ahead and add some wax to that look, it will be 10 times worse.

Guy Gagnon
Re: Polyurethane finishing
Guy Gagnon
JLMCDANIEL wrote:

I agree with Spruce, Minwax poly is garbage. The fact that the stain did not dry in several days suggests that the stain was bad. Blotchy usually means an uneven absorption of stain. 100 grit is a starting grit for leveling not for finishing. For a stain finish some do recommend lightly buffing with oooo steel wool to remove the luster.

Jack

Thanks for your response Jack. I think I'm getting too old for this because I screwed this job up completely. I am now thinking of rubbing it over with a good grade of paste wax to try to improve it's appearance. What do you think?

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