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Finish seems to be wrinkling
http://luthiersforum.com/forum/viewtopic.php?f=10101&t=47134		 Page 1 of 1
Author:  bcombs510 [ Sun Jan 24, 2016 10:40 am ]
Post subject:  Finish seems to be wrinkling
Hello,

I'm in the process of finishing the body and neck for this first build. Here is what I'm using:

General Finishes Endurovar
Earlex sprayer 1.5mm tip
Mineral spirits
400 dry and 600 wet paper
Body and neck pore filled with z-poxy

I sprayed 4 base coats and leveled with 400 grit dry, on the top only, to seal the top. I waited 30 mins between coats and 1 hour before sanding. I did this on Friday night. Left overnight and picked back up in the morning.

I sprayed 4 coats over the whole body and leveled with 400 grit dry. Also 30 mins between coats and 1 hour before sanding.

I sprayed 4 additional coats, slightly heavier, over the whole body and left overnight Saturday night.

Today, Sunday, I started my morning with leveling the body with 400 grit dry. I was able to remove 99% of the shiny with the 400 grit without going through so I felt OK with moving on to 600 grit.

I sanded the top and back with 600 grit wet with mineral spirits. Things worked as expected. I first used a swirl pattern then a second pass with the grain. The top and the back look as I would expect.

I started in on the sides using the 600 grit wet with mineral spirits. I did one side with swirl pattern, wiped it off with a cloth, and then turned the body over to do the other side. I went over the second side with the swirl pattern and wiped it off. I flipped the body over intending to take a pass with the grain and noticed what I first thought was an imprint of the carpet padding I'm using on the bench. But I don't think that it is an imprint because it's right in the waist which wouldn't be touching the padding. So it looks like the finish is maybe wrinkling. Any ideas what might cause this and what I should do about it? I added a bit of chalk dust to the pic here so you can see what is happening.

Image

Any ideas are appreciated!

Thanks,
Brad





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Author:  Alex Kleon [ Sun Jan 24, 2016 11:42 am ]
Post subject:  Re: Finish seems to be wrinkling
I haven't used EnduroVar for a guitar, but have sprayed many gallons of it for kitchen cabinets. I would spray a max of 3 light coats in a day, with at least 2-3 hours between coats. I'm pretty sure that there is a 100 hour cure time for the finish, so that, combined with the multiple heavy coats, might be the problem. As long as you don't exceed 24 hours, you don't have to sand between coats.

Alex
Author:  Barry Daniels [ Sun Jan 24, 2016 12:34 pm ]
Post subject:  Re: Finish seems to be wrinkling
Never used EnduroVar, but that definitely looks like overly thick, uncured finish that was topped by more coats that cured first.
Author:  bcombs510 [ Sun Jan 24, 2016 12:54 pm ]
Post subject:  Re: Finish seems to be wrinkling
Thanks, makes sense. I just went back down to take a look. It has flattened back out, but I can still see a faint imprint of the pattern you see in the pic, but I can no longer feel the ridges.

At this point, best bet is to let it sit for 24 and spray a few light coats using the timing Alex recommended?


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Author:  Alex Kleon [ Sun Jan 24, 2016 1:31 pm ]
Post subject:  Re: Finish seems to be wrinkling
Brad, I would give it at least a couple of days, and then do a scuff sand with 220 or 320 grit paper before recoating. After your final spray coat, leave it for 3-4 days before you start your final level sanding and buffing. Any wood finishing is an exercise in restraint. The finish line is in sight, and you want to get there ASAP, but this is where patience can really pay off. Hope it turns out great, for you!

Alex
Author:  Mike OMelia [ Mon Jan 25, 2016 10:58 am ]
Post subject:  Re: Finish seems to be wrinkling
"Today, Sunday, I started my morning with leveling the body with 400 grit dry. I was able to remove 99% of the shiny with the 400 grit without going through so I felt OK with moving on to 600 grit."

After one day's cure?

If you scuff sand, after a couple of days, and recoat, you will likely sand through the cured layer when leveling again. I've not seen this pattern you are showing happen, but it is hard to capture everything in a schedule. If that is an imprint, it should sand out. Imprints have happened to me before. So, I usually leave them hanging for several days. If it is wrinkling of the finish, it should sand out as well assuming you have a good number of layers on.

Patience. Wait for the cure. Then try and level it. You started the leveling way to soon.

Edit: There is always a "hands-on" experience associated with stuff like this. Ambient temperature, humidity. And just a general level of experience with the product. John Greven does all of his coats in a single day. He also claims to level the next, but I'm betting he's getting more time between coats. He did not explain his process. Just ticked a few lines off the list.
Author:  bcombs510 [ Mon Jan 25, 2016 1:59 pm ]
Post subject:  Re: Finish seems to be wrinkling
Mike O'Melia wrote:
Patience. Wait for the cure. Then try and level it. You started the leveling way to soon.


Hey Mike,

Thanks for the feedback. Yep, I totally messed up the steps. I was following what we had talked about in PM along with the steps here: viewtopic.php?f=10101&t=46913&p=621493&hilit=endurovar#p621493

What was stated was 4 coats, wait an hour, sand fairly flat. It seems what you intended was not a leveling there, but just take some of the nib down so the next coats are put on a fairly level surface. At the time I was putting my steps together I was thinking one hour and then completely level it and then more coats, 1 hour, and do the same. My bad. :)

Thanks for the help. I'll let it sit and pick back up on Tuesday with a few more coats. Then I'll let it sit a week before I do the final leveling.
Author:  Mike OMelia [ Mon Jan 25, 2016 2:24 pm ]
Post subject:  Re: Finish seems to be wrinkling
How many coats are on now?
Author:  bcombs510 [ Mon Jan 25, 2016 2:41 pm ]
Post subject:  Re: Finish seems to be wrinkling
Mike O'Melia wrote:
How many coats are on now?


I put four light coats on, half hour wait between each coat. Waited one hour and then level sanded with 400 grit. I got 99% of the shiny off on this step. Using 400 grit dry.

Next, I put on 4 more slightly thicker coats, half hour wait between each coat. Waited overnight and then level sanded with 400 grit dry. After I leveled it I moved on to 600 grit with mineral spirits. That is when the wrinkles showed up. I don't know if the mineral spirits hitting the finish that wasn't cured caused it to wrinkle or what.

To answer your direct question: I have 8 coats on there now. The top and back are level sanded. The sides pretty much are level sanded minus the spot where the wrinkles were, which will need some more light sanding. It basically flattened back out overnight last night, so I can still see where it wrinkled but cannot feel it.

Thanks for the help!
Brad
Author:  Mike OMelia [ Mon Jan 25, 2016 8:16 pm ]
Post subject:  Re: Finish seems to be wrinkling
Ok. I'm betting they shrink back even more. If got enough on, you may be ok. Let it cure a couple of days. Then see if you can smooth it out with 600. I'm not sure why you are swirling the paper. Take some green scotch brite to it, buff it a bit and see if you can see/feel it.

It's good you stopped when u did. Had you reached soft, uncurred finish, it would have been bad news.
Author:  Mike OMelia [ Wed Jan 27, 2016 8:38 am ]
Post subject:  Re: Finish seems to be wrinkling
Brad, here's a buff setup picture
Author:  bcombs510 [ Wed Jan 27, 2016 11:52 am ]
Post subject:  Re: Finish seems to be wrinkling
Cool. Thanks!

My buffer shows up tomorrow so I'll play around with mounting it.
Author:  Mike OMelia [ Thu Jan 28, 2016 10:13 pm ]
Post subject:  Re: Finish seems to be wrinkling
How's that new buffer?
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