Polycrylic table top scratches off


PK318

Recommended Posts

I refinished our kitchen table. For the finish I used Minwax water base Polycrylic because I'm pretty new at applying poly finishes and heard this was easy to apply. And it was, went on beautifully. Followed directions to a T. Did 5 coats. Let it cure for 5 days before bringing it up for use. It got bumped on the way up the stairs and looked like it had some paint transfer so I scratched it off but it was the polycrylic and it scratched right off. Within 24 hours it got another scratch and the poly came right off again. 

Did I do something wrong? Is it just a crappy finish? I know it should not just scratch off. The wood doesn't get damaged or scratched, the poly just scratches off. 
Any ideas how to fix this, i.e. can I put a coat of a better finish on top or do I have to start all over, would be GREATLY appreciated. 

It's a huge downer considering how gorgeous the table turned out!


 

Link to comment
Share on other sites

You say it was a refinish.  Waterbornes are prone to adhesion problems on contaminated surfaces.   Strippers usually contain wax/silicone like substances to slow evaporation and keep them thick.  That is my first guess.  If you scraped/sanded the old finish, then you might have left some contamination behind.  And if you stained your table you might have compatiability issues.

Unfortunately I think you need to start all over.   To be safe user a barrier coat of dewaxed shellac before applying your top coat.  

Link to comment
Share on other sites

You say it was a refinish.  Waterbornes are prone to adhesion problems on contaminated surfaces.   Strippers usually contain wax/silicone like substances to slow evaporation and keep them thick.  That is my first guess.  If you scraped/sanded the old finish, then you might have left some contamination behind.  And if you stained your table you might have compatiability issues.

Unfortunately I think you need to start all over.   To be safe user a barrier coat of dewaxed shellac before applying your top coat.  

So the dewaxed shellac goes on top of the stain and before polycrylic? 

Link to comment
Share on other sites

They call it polycrylic but I'm guessing it's mostly acrylic (and little to no poly) which isn't usually recommended for table tops and floors. For those applications you want a more durable water-based poly finish.

You said you refinished. What prep did you do for that? Not knowing what was previously on the table, even if you stripped back, a sealer coat of dewaxed shellac would have been a good idea.

As to repairing it I don't know if putting poly over the acrylic would be a good idea. You are going to end up with a lot of layers which can cause problems. It might be safest to strip down and start over.

Link to comment
Share on other sites

So the dewaxed shellac goes on top of the stain and before polycrylic? 

yes.  also make sure the stain and polycrylic are compatable.  Some aren't.  Minwax is pretty good about disclosing compatability issues (I think polycrilic can't go over the red mahogany stain, for instance).    When in doubt check with the manufacturer.  

I used stripper, scrubbed with steel wool and sanded it down good. 

Do I just need to use a oil based Polyurethane? 

after using stripper, wiping with mineral spirits and cleaning with Tri Sodium Phosphate is a good idea.  

All finishes other than shellac will have problems if there is any residue from the stripper.  Shellac has the best chance of adhering to wax or silicone.  

Link to comment
Share on other sites

Two more things:

1. The instructions say not to use steel wool under it. Steel wool can contain oils to keep it from rusting. 

2. The instructions say not for floors which I would consider also not good for table tops which get a lot of abuse. I would use a poly instead. 

That is helpful.  I never really thought too hard about the difference between a waterborne polycrylic, waterborne lacquer and waterborne polyurethane.  I just assumed they were marketing BS for the same thing.  

Link to comment
Share on other sites

Two more things:

1. The instructions say not to use steel wool under it. Steel wool can contain oils to keep it from rusting. 

2. The instructions say not for floors which I would consider also not good for table tops which get a lot of abuse. I would use a poly instead. 

Wow. I had no idea. I'm, obviously, a beginner at refinishing. So my best bet is to strip off the polycrylic and use a polyurethane? Do I still need to use a dewaxed shellac between the stain and poly?

Link to comment
Share on other sites

Wow. I had no idea. I'm, obviously, a beginner at refinishing. So my best bet is to strip off the polycrylic and use a polyurethane? Do I still need to use a dewaxed shellac between the stain and poly?

I think shellac is a good idea on most refinish jobs.  You can apply it before and/or after the stain.   If you do it before the stain,  a very thin coat will seal of contaminants and also result in more even (but less intense color).  You can also do it after the stain, which will help seal in the stain and speed up your overall finishing schedule.  Shellac dries super fast (like 15 minutes fast) and acts as a first coat of finish, so you can eliminate one of your coats of poly (which takes longeer to dry).  

Link to comment
Share on other sites

  • 3 weeks later...

5 coats seem a little much and could be the problem exceeding mill thickness of the finish if you didn't sand back. Did you let each coat dry and did you sand between coats? Water-based finishes do need a mechanical bond to stick, however, they do "burn" in some. But the scratch of 320 grit paper gives the finish tooth so the fresh finish has something to hold on to.  

-Ace-

Edited by AceHoleInOne
Link to comment
Share on other sites

Wow. I had no idea. I'm, obviously, a beginner at refinishing. So my best bet is to strip off the polycrylic and use a polyurethane? Do I still need to use a dewaxed shellac between the stain and poly?

From what I have heard it is rarely a bad idea to add in a layer of shellac if there is any concerns about compatible finishes.  It is treated as a universally adhesive layer.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   0 Members, 0 Anonymous, 44 Guests (See full list)

    • There are no registered users currently online
  • Forum Statistics

    31.2k
    Total Topics
    421.8k
    Total Posts
  • Member Statistics

    23,759
    Total Members
    3,644
    Most Online
    R Parekh
    Newest Member
    R Parekh
    Joined