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CRC
08-15-2010, 01:13 PM
I've been using Sure Finish as a final polishing compound for spot repairs that include basecoat and clearcoat blending. My process is to pre-sand the repair area for the new clearcoat with 800 grit and there is usually about a 1 inch sanded line left around the area after the c/c is applied. After the c/c cures I wet sand with 1200, 1500, and 3000 Trizact beyond the repair area, then I buff the whole area with a wool pad and Sure Finish and everything looks super fine including the small 800 Grit area around the repair.

I've had a couple of repairs where after a few weeks and/or washes the 800 grit area shows up again. I'm thinking that I probably didn't get to the bottom of the scratches in my sanding steps but it looked good at the time. My guess is that the Sure Finish may have masked the defect until enough wore off to show it. Any suggestions to aviod this in the future and not affect the new paint?

Bob K
08-15-2010, 02:31 PM
I scuff and clear the entire panel, which includes when I do a quarter going all the way up to the windshield. That avoids a lot of problems. I guess itís extra work but that is how I avoid the problem you are having. It also insures that I wonít get a line in the future where the new clear has ended on the panel.

Not saying you should do this, I donít know how pressed for time you are, but I donít mind spending the extra time and a little more clear coat.

Bob K

Len
08-15-2010, 11:16 PM
I've been using Sure Finish as a final polishing compound for spot repairs that include basecoat and clearcoat blending. My process is to pre-sand the repair area for the new clearcoat with 800 grit and there is usually about a 1 inch sanded line left around the area after the c/c is applied. After the c/c cures I wet sand with 1200, 1500, and 3000 Trizact beyond the repair area, then I buff the whole area with a wool pad and Sure Finish and everything looks super fine including the small 800 Grit area around the repair.

I've had a couple of repairs where after a few weeks and/or washes the 800 grit area shows up again. I'm thinking that I probably didn't get to the bottom of the scratches in my sanding steps but it looked good at the time. My guess is that the Sure Finish may have masked the defect until enough wore off to show it. Any suggestions to aviod this in the future and not affect the new paint?

When you're going to blend single stage or clear you should use a VERY FINE scratch well beyond the planned blend. I usually don't use anything more coarse than 1500. I cover the area, blend out the paint then dust straight slow reducer over the edge of the blend. Allow the paint to cure well then polish. Trying to buff 800 scratches out of hard urethane is quite difficult and unnecessary for this process.

CRC
08-16-2010, 10:12 AM
Thanks for the replys - Len, I agree with you but I'm a little confused as most threads about blending c/c do use much finer sanding to prepare for it. What bothers me is the Product Data instructions for the Sherwin-Williams clears that I use all say to use coarser grits to be sure the clear has enough to hang on to. Have you seen any problems after using finer grits?

Len
08-16-2010, 12:08 PM
Thanks for the replys - Len, I agree with you but I'm a little confused as most threads about blending c/c do use much finer sanding to prepare for it. What bothers me is the Product Data instructions for the Sherwin-Williams clears that I use all say to use coarser grits to be sure the clear has enough to hang on to. Have you seen any problems after using finer grits?

In most cases (SW may be different) clear will bond to very fine scratches, even dulling with cleanser can give you enough tooth for the clear to adhere to. The problem with using a more coarse grit is that it causes the very problem that you're having, it can be very difficult to polish out these types of scratches after the paint gets hard.

Kent
08-24-2010, 07:23 AM
I like using scuff paste on a paper towel to scuff clear blend areas. It gets it clean and put the right amount of scuff into the panel. After it cures, you can sand it with 2000g and buff and hopefully it won't pull back on you.

Henry
08-24-2010, 09:52 AM
gonna try to cut in a jamb that's busted on a vette next week just to see if I can...
Think it will be ok since it won't get much UV light exposure.

Did you intend on a new thread? What does what you said have anything to do with the question posted? Do hope your cut in comes out well. Henry