Redwood and Polyurethane Topcoat, still has not dried, thoughts and solutions?

[Erik G]

Hello all,

So here are the details:

• building a table, using redwood and pine ply. redwood is the table top, and pine for the shelves and supports.
• Construction grade redwood milled down and dried for about a week as the other parts of the project were coming together.
• Applied one layer of poly, let sit for 24 hours and applied the second coat
• After a week of curing, the poly still has not cured on the redwood, but seems to have cured fine on the pine used elsewhere in the project.

The poly is peeling up and can be removed like wax on a surf board. When i remove it by rubbing my finger on the wood, it appears i am getting down to the original wood layer, which has a tacky and uncured feel to it. At first it was only in spots where the poly was showing that it was a bit thicker than others, but after some sanding to smooth everything out, the poly peels everywhere by rubbing or putting any pressure on it. the peeling is limited to the redwood, the other wood(pine) is ok.

Here are my thoughts:

• I applied a coating that was too thick or didnt give enough time to curing before the second layer.
• Used store brand poly and it seems to not be the same quality as a helmsman or other brands.
• The redwood is still wet or some of the oils are not preventing the poly to adhere properly. This is my bet as the problem.

Here is my plan:

• Remove the poly by sanding or stripping. Preferably sanding as the pine is ok and i dont want to damage its finish.
• Either apply a sanding sealer and then recoating?
• Wait a month or so for it to dry? not the best option as this was supposed to be a birthday gift for someone.
• Other options?

So my question to all of you helpful folks, what are your recommendations? Sand it all and let it dry? Apply some other coating? This table will be used to prep food so it needs to with withstand some abuse. I will post pictures when i get home. 

Thanks for all your help and input. 

-Erik

[wtnhighlander]

If the poly is rubbing of as easily as you say, wet wood is my guess as well. You said construction grade redwood, which raises a big red flag. Construction material typically is not dried the same way 'furniture grade' hardwoods are dried. When I buy construction lumber at my local home center, I typically have to wait several weeks or even months for it to become stable. You might try wiping the bare wood with acetone to remove any surface oils, then apply a seal coat of shellac. If that doesn't peel off, then the poly should stick.

[Erik G]

Thanks mike.

I'm not a huge fan of contraction wood but have had good luck in the past but it wasn't redwood. I'm working on removing it now and I'll start over. 

I didn't think about using shellac as a first coat. Maybe that will help keep moisture out and allow the poly to stick. Is there a better top coat than poly for a table top or should I just be patient and try poly again after some drying time? 

[wtnhighlander]

Unless you want a thick epoxy coating, poly is a good choice for table tops.

[Ronn W]

My semi-educated guess is that oils from the redwood, the same stuff that makes it weather so well is interfering with your finish.  I put up a cedar fence a few years ago and the installer made a point of telling me to let the wood be out in the open uncoated for several weeks before trying to paint it.

[Erik G]

Ronn- I am starting to think the oils and the wetness both contributed to the lack of sticking. Im in the process of removing the bad poly and will rethink this. Probably will let it sit for a while and apply some wipe on poly as a first and second coat and then go with slightly thicker coats of regular poly. 

I didnt want to use a chemical stripper and i found that a heat gun and plastic spatula work pretty well at removing the poly. 

Thanks for your input everyone. 

-Erik