Polyurethane help

[justin waldron]

So I had this conference table to refinish and by the second picture you can see how the poly has "puddled"..  Here is what I did and any help would be so appreciated, I used no strippers to remove the old finish:

220 grit and min. spirits to cut through the old poly

150 to 220 grit to sand through the old stain

Used General Finishes sanding sealer

Used Gen. Finishes water based stain and waited 24 hours before my first coat of poly.

sanded the first coat (which had puddles) with 500 grit

Applied second coat and have these puddles. 

 

The table is made of particleboard with a thin veneer of cherry on top, I was afraid to use any chemical strippers, I figured it would pop the veneer or break the partcile board down. 

[David Dean]

well do what the bad news first or the good it's all got to go the old stain and ploy right down to the wood. Well there anit no good news.

[David Dean]

Oh one more thing after you get throw sanding you'll need a spray bottle of water and lighty spray it on the wood and what this well do will rasie the grin up and you get to sand again but there whot be any old stain or ploy and which for the stain and ploy reacting to each other mimi-wax has that problem with there stains to.

[Don Trust]

Justin,

 

Not sure I understand what you mean by 'puddles', but most if not all problems with one finish adhering to another can be solved with an application of dewaxed shellac.  One thin coat is usually all you need.

 

I've put waterbased finishes on top of oil based finishes by putting a coat of shellac down between them.  Works a charm. (I know you are not doing that, but it just shows what shellac can help with)

The waterbased stain and the poly you are using may not be completely compatible.  a coat of shellac between them should help.

 

One other thing that may be at work here is the drying time.  Depending on the humidity and such, 24 hours may not be enough.  I've had times recently that the stain had to dry for 3 days before it was truly ready for a finish.

 

 

 

 

[justin waldron]

Don, the effect I was actually getting was fish eye.  Apparently it's cause by contamination, but I have sanded it down twice now and can't do any more because the top is veneer.  Thanks for your help though.

[Don Trust]

Justin,

 

Ah, I have never experienced the fish-eye problem.  I understand, as you say, it is caused by contamination, usually silicone or some type of oil.

 

I know it's expensive, but I have had wonderful experiences with Formby's Furniture Refinisher for removing old finishes with out the need for sanding.  NOT the gel type, use the liquid type that is the same consistency as water.  It works great!  As it removes the finish it also manages to smooth out the color of the stain and make it more uniform.  You have to experience it to know what I mean there.  I won't use any other stripper.  I've used Formby's many times with veneer with no problems at all.

 

If you have already sanded the surface, which you have, after the Formby's you won't need to sand again.  Usually, I can only find it at Lowes.

 

[justin waldron]

I've used Formbys before and you are right, it works great, but I have had my fill already on this table. haha, at this point I'd rather rebuild the top. 

[Don Trust]

Oh boy, been there before.  Sometimes you want to get out the matches :-)

 

Happy trails.

[justin waldron]

Yeah, at this point I have tried everything that I can think of and can't really put any more time into trying to figure it out.  With that being said, if they aren't happy I will just build one out of solid cherry.   Thanks for the insight though!!!!

[Jay Boutwell]

Hello Justin.  I would suspect that your finish problems are coming from a furniture polish of which contains silicone.  This is one of the most difficut things to remove from wood.  I have ran into the problem before refinishing furniture and other wood items expecially the ones with the unique carvings.  I have in the past had good luck using a product from the automotive painting and refinishing world.  It is called "Naptha" and another one is called "rapid prep".  Often times when the wood is finished it is buffed with a polish and a buffing wheel to get a high shine.  This makes it very difficult to remove as a light sanding also drives the silicone type waxes deep into the wood.  The surface in your photo is definateley fish eye and you get this same pattern in automotive finishes that have not been properly prepared before the paint is applied.   I have never had luck with sanding sealers as they will not stick to the surface either and will fisheye just like the poly did.  You have to get the contaminate agent out of the wood.  This is why I also suggest using white vinegar and water in about a 50/50 mix to remove glue around wood joints while the glue is still wet.  You don't always see the glue until you apply the finish.  Using plain water on glue actually drives the glue into the wood pores where the vinegar prevents it from sticking.

 If all else fails this is the approach I would take.  I would wash it down and dry it then sand it lightly and wash again with the naptha or rapid prep. Dry it throughly before application of finish.  You might be surprised at the difference.  Since it is particle board talk them into using a high grade laminate and apply it over the well sanded surface laminates are tough and are resistance to normal things found at a conference, like coffee, soft drinks and the occassional member whom attends the conference and is agitated and used his pen or pencil to dig a hole in the surface.  I have seen this happen more times that once.  It is a good quick fix and looks good too.

Good luck , sorry this one is being a problem.

[justin waldron]

Hey Jay!  I appreciate the insight.  I haven't refinished a ton of furniture in my day, but I surely hit the wall on this one for sure. I didn't even know a thing such as "fisheye" even existed.  I have spoken to them about the table and they are very understanding.  If they aren't satisfied with it, I told them I would rebuild the top out of solid cherry and be done with the particle board, the veneer and all those years of silicone based polishes that were applied to the table.  I will have to wait and see what they think, it's being delivered tomorrow. 

[justin waldron]

Ok, I have it "fixed" better than what it was.  After the fish eye came back I put on 4 coats of wip on poly to build the finish up.  After letting that cure, I used 220 grit and sanded the finish flush and used 0000 steel wool and mineral spirits to try and clean, then went back with a 50/50 cut of poly and mineral spirits.  The eyes are still noticeable, but the finish is at least uniform at this point.  My next project for them is to build a locking bookcase with doors, I won't let them use furniture polish on it before I begin my finishing, that's for sure!!!!

[justin waldron]

This is what I ended up with.  I'm going to do one more coat of poly and then call it quits.