StewMac tools

Nitro finish curing problems

TEST ON SCRAP FIRST! If your question is about repair work, either regluing or refinishing, please post it in our Repair Section.

Nitro finish curing problems

Postby Robert Freemond » Wed Aug 16, 2017 10:46 am

Just finished my first serious Lacquer job & it's not curing. After three weeks I sanded & buffed it out to a very nice finish, but after a couple of weeks you can see that it's still moving.
I now know that I put on too much too soon so - will it ever cure Or should I just strip & start over.
Robert Freemond
 
Posts: 95
Joined: Tue Jan 24, 2012 4:11 am
Location: Van Nuys Ca.

Re: Nitro finish curing problems

Postby Barry Daniels » Wed Aug 16, 2017 11:09 am

What brand?
MIMF Staff
Barry Daniels
 
Posts: 1675
Joined: Thu Jan 05, 2012 10:58 am
Location: Houston, Texas

Re: Nitro finish curing problems

Postby Robert Freemond » Thu Aug 17, 2017 12:10 am

Lawrence McFadden
Robert Freemond
 
Posts: 95
Joined: Tue Jan 24, 2012 4:11 am
Location: Van Nuys Ca.

Re: Nitro finish curing problems

Postby Aaron Helt » Thu Aug 17, 2017 8:13 am

What do you mean by "moving"?
Aaron Helt
 
Posts: 48
Joined: Thu May 10, 2012 9:19 am

Re: Nitro finish curing problems

Postby Barry Daniels » Thu Aug 17, 2017 11:09 am

When you say McFadden's it means that the lacquer is several years old. Usually that is not a problem, but it is something to consider.

So, how many coats did you apply, how thick is the finish, and how much drying time did you allow between coats? What did you use for thinner? How humid is it in your shop?
MIMF Staff
Barry Daniels
 
Posts: 1675
Joined: Thu Jan 05, 2012 10:58 am
Location: Houston, Texas

Re: Nitro finish curing problems

Postby Robert Freemond » Fri Aug 18, 2017 11:46 am

Hi every one & thanks for the response.
Berry,
The Lacquer was a couple of years old, I used Home Depot Thinner, I'm in So. California, It'b been Hot & the humidity varies daily.
My paint schedule was: First 2 coats thinned 50/50, following coats every 1-1/2 hrs. for a day.
second day - sand & repeat. for 3 days.
I have since learned that It was too much too fast so my question is, will it ever cure, or should I start over

Aaron, A couple of weeks After I sanded & buffed, the surface was becoming textured & was no longer perfectly flat.
Today if I press hard with my thumb nail It will leave a small mark.
Robert Freemond
 
Posts: 95
Joined: Tue Jan 24, 2012 4:11 am
Location: Van Nuys Ca.

Re: Nitro finish curing problems

Postby Barry Daniels » Fri Aug 18, 2017 12:25 pm

The cheap big-box thinner is likely the problem. I had an issue with it once and it messed the lacquer up good. I had to refinish. It's a good idea to use quality thinner and I followed someones recommendation to go with Sherwin Williams thinner. SW has thinner with various degrees of retarder that is useful in my humid conditions in Houston. They provide thinner for professional finishers who are more demanding than the diy folks.

I would say that if your finish is still soft after 3 weeks, it will never cure properly. You will probably get a cured finish quicker if you strip and refinish.
MIMF Staff
Barry Daniels
 
Posts: 1675
Joined: Thu Jan 05, 2012 10:58 am
Location: Houston, Texas

Re: Nitro finish curing problems

Postby Aaron Helt » Fri Aug 18, 2017 12:58 pm

Yep, agreed. Home store lacquer thinner can have anything in it. I bought a consumer brand name from a store one time that was oily and had a orange tint to it. I used it to clean stuff but no way I'd put it in lacquer. Crown and major paint manufacturers have the real stuff.
As far as if it will harden up in time, only time will tell.
Aaron Helt
 
Posts: 48
Joined: Thu May 10, 2012 9:19 am

Re: Nitro finish curing problems

Postby Robert Freemond » Fri Aug 18, 2017 2:36 pm

Berry, what's the purpose of using a retarder in humid weather.
Robert Freemond
 
Posts: 95
Joined: Tue Jan 24, 2012 4:11 am
Location: Van Nuys Ca.

Re: Nitro finish curing problems

Postby Barry Daniels » Fri Aug 18, 2017 3:17 pm

Retarder slows the curing so water has a chance to get out of the finish. This prevents blushing. Many lacquer thinners have retarders in them. The Sherwin Williams thinner I use is formulated for humid climates by including a certain amount of retarder.

You may not have had blushing in your lacquer, but eventually you will when the conditions are right.
MIMF Staff
Barry Daniels
 
Posts: 1675
Joined: Thu Jan 05, 2012 10:58 am
Location: Houston, Texas

Re: Nitro finish curing problems

Postby Robert Freemond » Tue Aug 22, 2017 12:23 pm

If Lacquer can so problematic what do you folks think of Water based lacquer like KTM 9 ( I know it's discontinued).
Robert Freemond
 
Posts: 95
Joined: Tue Jan 24, 2012 4:11 am
Location: Van Nuys Ca.

Re: Nitro finish curing problems

Postby Aaron Helt » Tue Aug 22, 2017 1:18 pm

IMO, nitro lacquer is the easiest, most trouble-free finish there is.
Aaron Helt
 
Posts: 48
Joined: Thu May 10, 2012 9:19 am

Re: Nitro finish curing problems

Postby Gordon Bellerose » Tue Aug 22, 2017 3:32 pm

Robert Freemond wrote:If Lacquer can so problematic what do you folks think of Water based lacquer like KTM 9 ( I know it's discontinued).

I use water base lacquer only.
I find it easy to use, easier than nitro to deal with, (fumes, extreme flammability, clean-up) and readily available.
I have not used KTM 9. I have used Target EM-6000, and am now using Britetone.

Here in Canada, our VOC laws are quite strict. There are many conditions that must be met before you can use solvent based products.
I need your help. I can't possibly make all the mistakes myself!
Gordon Bellerose
 
Posts: 918
Joined: Wed May 30, 2012 11:47 pm
Location: Edmonton AB. Canada

Re: Nitro finish curing problems

Postby Barry Daniels » Tue Aug 22, 2017 5:50 pm

Making a blemish free, high gloss, quality finish is a challenging process no matter what kind of finish you use.
MIMF Staff
Barry Daniels
 
Posts: 1675
Joined: Thu Jan 05, 2012 10:58 am
Location: Houston, Texas


Return to Glues and Finishes

Who is online

Users browsing this forum: No registered users and 1 guest

Your purchase from these sites helps support the MIMForum, but only if you start at the links below!!!
Amazon music     Amazon books     Amazon tools     Rockler tools     Office Depot    

The MIMF is a member-supported forum, please consider supporting us with a donation, thanks!
 • Book store • Tool store • Links • 
cron