Urethane won’t dry - Router Forums
 15Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 21 (permalink) Old 06-01-2015, 12:09 PM Thread Starter
Registered User
 
Join Date: Jun 2011
Country: United States
First Name: Barry
Posts: 592
 
Default Urethane won’t dry

I have been making a set of coasters to go along with an oval cheese board. The coasters are the same design except they’re round and I used the opposite combination of wood for the coasters. They are made from Maple and Padauk and are 4” round X ¼” thick. I will attach self-adhesive cork on the back once they are finished. My problem is with the finish. I usually find finishing the most challenging part of my projects.

A brief background; my house is on the market and I’m trying use up what I have on hand before the move. This was all good wood but I was limited in my choices.

I decided to finish the coasters by first giving them a couple of coats of natural Danish Oil. I then waited 3 days for the Danish Oil to set up then used a rattle can of Minwax Gloss Spar Urethane. The final coat was going to a satin Polyurethane. My problem is that, after a week, the Urethane over the Padauk strips is still tacky. It’s dry on the Maple. I may have not let the Danish Oil dry long enough, I may have sprayed too heavy a coat onto the Coaters or the Urethane may have been too old. I don’t know if rattle cans go bad or not.

Knowing what went wrong would be interesting information, so I don’t repeat the error in the future, however, the important question is: “What do I do now?” Starting over is not an option. I’m out of the Padauk. Should I try to rub off the finish with Mineral Spirits, should I sand it down to take of the Urethane, or is there some tried and true method of getting the Urethane to harden? At this point I’m stuck and would really appreciate any suggestion as to how to save this project. It’s being made as a gift and we’re going to see the recipients in about 2 weeks.
Attached Images
 
Barry747 is offline  
Sponsored Links
Advertisement
 
post #2 of 21 (permalink) Old 06-01-2015, 02:11 PM
Registered User
 
DaninVan's Avatar
 
Join Date: Dec 2011
Country: Canada
First Name: Dan
Posts: 14,943
 
Default

I know a lot of guys get away with all sorts of strange combinations as attested to on the Forums, but ever since Polyurethane came out (in the late 50's?). the generally accepted wisdom was that applying poly over any other finish was an invitation to disaster. I stuck to that policy and I've never had a problem. "Finish" of course doesn't mean you can't use an appropriate stain...but not with an oil base that needs to cure.
Just my opinion...
Personally, I'd strip it and start the finishing over.

ps in a discussion up here last week, the topic of 'Danish Oil' came up. It turns out there is no one formula for it. Manufacturers use whatever they deem appropriate for ingredients, although Tung oil sees to be most popular(?). If that's the case then you might get away with using one brand + poly, but not necessarily another.
DaninVan is online now  
post #3 of 21 (permalink) Old 06-01-2015, 02:14 PM
Registered User
 
DaninVan's Avatar
 
Join Date: Dec 2011
Country: Canada
First Name: Dan
Posts: 14,943
 
Default

It just occurred to me that if there's any wax in the 'Danish Oil' stain, Polyurethane won't stick, or at least it won't cure.
DaninVan is online now  
Sponsored Links
Advertisement
 
post #4 of 21 (permalink) Old 06-02-2015, 05:49 AM
Registered User
 
Join Date: Jun 2011
Country: United Kingdom
First Name: Andy
Posts: 577
 
Default

Given that the poly set on the maple parts, I think it's insufficient curing time for the oil. I guess it soaked into the two woods differently and that resulted in slower curing on the padauk. I know the Danish oils I use take a long time to cure, like a week before it feels hard when you tap it with a fingernail.

As Dan said I think you'll have to strip the poly. Not sure of the best way to do that. The cured poly on the maple would resist many solvents. Paint stripper would do it but sanding might be the best bet. Then re-oil and wait a bit longer before over-coating. There is a lot to be said for testing the finish on scraps first, especially if you're using a new combination or old stock.

I love the design of the coaster by the way, it looks great. Hope you manage to resolve the finishing difficulties in time, I'm sure the recipient will be very pleased with them.
AndyL is offline  
post #5 of 21 (permalink) Old 06-02-2015, 09:49 AM
Registered User
 
Join Date: Oct 2013
Country: United States
First Name: PAD3
Posts: 47
 
Default

Use oil very sparingly, just enough to change or highlight the grain and then cover with un-waxed shellac as a sealer coat immediately. The oil will cure under the shellac, which dries very quickly, and poly will adhere to shellac without a problem and dry at it's normal pace.

Just remember the shellac must un-waxed.
PAD3 is offline  
post #6 of 21 (permalink) Old 06-03-2015, 09:26 PM Thread Starter
Registered User
 
Join Date: Jun 2011
Country: United States
First Name: Barry
Posts: 592
 
Default

Thank you all for your suggestions. I'm sort of taking all of them. I used mineral spirits to wipe off the spots that were still tacky. After letting them dry and continue to harden overnight, I sanded with 150 then 220 grit sand paper and have given them 2 coats of Zinseer Sealcoat. Tomorrow I'll lightly sand the shellac and put the first of 2 coats of poly on them. After they dry I'll put the cork on the back and complete the stand using the same sequence of finishing. Due to other commitments, I probably won't get them completed until next week but, once done, I'll post some pictures.

Thank you again for your help. I've learned a valuable lesson from this and, to me, that's what woodworking is all about.
Barry747 is offline  
post #7 of 21 (permalink) Old 06-04-2015, 12:07 AM
Registered User
 
DaninVan's Avatar
 
Join Date: Dec 2011
Country: Canada
First Name: Dan
Posts: 14,943
 
Default

Good luck with the restoration, Barry!
DaninVan is online now  
post #8 of 21 (permalink) Old 06-04-2015, 07:22 AM Thread Starter
Registered User
 
Join Date: Jun 2011
Country: United States
First Name: Barry
Posts: 592
 
Default

Quote:
Originally Posted by DaninVan View Post
Good luck with the restoration, Barry!
Thanks Dan.
Barry747 is offline  
post #9 of 21 (permalink) Old 06-04-2015, 05:48 PM
Registered User
 
DaninVan's Avatar
 
Join Date: Dec 2011
Country: Canada
First Name: Dan
Posts: 14,943
 
Default Earworm

"Urethane won’t dry"


I've got My Boomerang Wont Come Back as an earworm now;
thanks a lot!
DaninVan is online now  
post #10 of 21 (permalink) Old 06-05-2015, 08:37 AM Thread Starter
Registered User
 
Join Date: Jun 2011
Country: United States
First Name: Barry
Posts: 592
 
Default

Quote:
Originally Posted by DaninVan View Post
"Urethane won’t dry"


I've got My Boomerang Wont Come Back as an earworm now;
thanks a lot!
Sorry, the coasters are the wrong shape to return when thrown. I was almost ready to check that out, too.
Barry747 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Router Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
It sure gets dry in west texas Jerry Bowen Lobby 20 12-23-2013 03:19 PM
Air dry small quantity of wood indoors? Barry747 New Member Introductions 12 10-21-2013 07:07 AM
Is it dry now? awoodnut Wood Species 7 12-10-2010 05:17 PM
wipe on urethane jd99 The Finishing Touch 13 09-25-2009 07:28 PM
Urethane over Shellac pmspirito The Finishing Touch 3 11-14-2005 09:25 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome