• Having site issues? Contact Dub@southernPolyurethanes.com

Burn Through Question

So tonight I figured out how much sanding and buffing was too much and burnt through right in the middle of one of my doors.

I had a real nasty run that I sanded out probably too soon, then it sunk down and I didnt catch it till I buffed. I re sanded the area pretty aggressively to get it back level and while on my initial cut burnt through. I have base, 3 coats of clear, then some base blended, and 4 coats of clear. Ive burnt through the 4 coats of clear to my base blend.

Do I need to do anything other than spot in some base and then re clear the door? Ive never had a burn with a ring like this before. Base was activated.



Paint Fanatic
Staff member
No you have the plan right, just do a medium coat of base over the spot and walk away for 30 minutes, than do second coat the same way just to prevent any frying, unlikely at this stage you would fry but better safe than sorry.
Thank you sir.

Now I just have to decide if I want to try and mask and do the outside skin or the whole door. I'd just as soon not have a tape line I guess, I'm not sure where to mask the back side as I seam sealed the pinch weld.
I thought about that, then saw another run on the back side and just decided to sand the whole thing with 600. Ill hit it with a scuff pad and clear everything minus the window frame, that actually came out good.

This whole mess was caused by a temp swing, one day I cleared my fenders, it was hot and things were going on kind of dry so I opened up the gun a little bit and really got them to go pretty good. Next day I used that setting to start, but the temp had dropped as a front went through overnight, and I totally hosed it on my first door. Because of this my starting point is now a 1/4 turn lower then it was. Somethings you learn the hard way when your trying to find a baseline and have never seen how the weather can change things.
I had a question for you guys based on today's results on this door.

I was wondering is clear more prone to sagging or running on the initial coat of a flow coat? Clear sanded down with 600 and cleaned. Or am I imagining things?

It just seems like I run into sags/runs on that initial coat, then I make a small adjusment, 1/4 turn in on fluid and 2 more psi, and it almost looks like I could have stayed with my initial settings.

I had this problem on the door the first go around a month ago at 3 turns on fluid, so I started off at 2.75 today as that worked out good on the last 2 coats back then. Today I ended up in sag city at 2.75 so I went to 2.5 and it seemed just ever so slightly dry after that.

I know it is stated to spray the first coat like you want it to look, but Im tempted to start out a little dryer and work up after I have some fresh clear on the door to hold things in place.

Man this stuff is tricky, I feel like its a razor's edge on having it lay out good, running or being dry. I felt like superman on the first coat, It really went on nice and looked good, I walked around the door and came back around and there they were, pretty deflating when you think its going all to plan.
Well a month later and all that work down the drain, back in the same spot trying to get a black piece of string out. No idea where it came from but of coarse it was right by the exterior door key lock cylinder, so pretty visible. Good news is the string is gone, but I have a nice halo now.

I'd like to only do the outside skin, but I'm not entirely sure how to mask it. What exactly is back masking? Can I just use 2 inch tape, have an inch and a half on the door and a half inch over hang off the back side of the door, or will this not work. Looking for any info as I've never done a masking deal like this before. Thanks