Need your suggestions - Final steps in Rock Chip repair

[tguil]

Need your suggestions - Final steps in Rock Chip repair


I posted this on MOL but would appreciate some help from you Autogeek folks. No pics. My camera doesn't do macro and black very well.

I need a bit of specific help on the final steps of repairing a 1/4 chip on my black Harley's rear fender. (Yes, I did a search.)

I have layered several coats (maybe even ten) of black Harley Davidson paint into the chip over the past three days. I used the technique where you fill the chip leaving paint higher than the damage with the intent to sand it down. I now have a nice "blob" ready to be taken down and buffed. I'll be using Meguiar's Unigrit 1500 and 2000 blocks.

I plan to mask around the "blob" for the initial take take down. I'll come withing a 1/4 inch of ithe "blob" with the masking tape.

Because the paint is pretty darn thick, how long should I wait to start the sanding? The temperatures have been in the 70's and 80's the last couple of days. The touchup paint is acrylic lacquer. I did not use any clear coat. I think that the basecoat will polish up just fine. Right now I have a "shiny blob".

Although I have been doing touch up for years (fifty of them), I have never used Unigrit blocks before. I know they need to be soaked over night and I know that I need to use shampoo as a lubricant with the water.

I don't see any problems with polishing out the 2000 scratches. I've done that lots of times. The "blob removal" is my main issue.

 

[kvnkst]

Re: Need your suggestions - Final steps in a chip repair

I'm curious on this one too! Good post

 

[BobbyG]

Re: Need your suggestions - Final steps in a chip repair

Welcome to Autogeek!

Filling in chips takes allot of patients and a steady hand.

Wrap some 1000 grit wet dry paper around a small file or something that will give you the control you need not to touch the paint adjacent to the area your trying to sand.

Use plenty of water and carefully wet-sand the blob down. When you get close change the paper to 1500 and continue until it's blended pretty well. Finish up with 2000 then try polishing it as best as you can.

The existing paint more than likely has a clear coat and you don't want to damage it so proceed very slowly. I theory this should work but depending on the skill and steady hand will determine the final outcome.

Autogeek offers this product for chip repair.

Dr. ColorChip Paint Chip Repair, repair paint chips, touch-up paint, Doctor Color-Chip Paint Chip Repair

 

[Mike PhillipsMike Phillips is verified member.]

Re: Need your suggestions - Final steps in a chip repair

Don't I have anything posted on MOL on this topic?


I tend not to like this topic because most people don't understand how much work and time will go into a spot about the size of a pea and yet they will want it to look like it was never worked after all is said and done.

I know that doesn't describe you Tom but it does describe a lot of non-detailing car owners.


Painter's Tape
The painter's tape technique is a good idea.. placing some painter's tape around the blob of paint so for your initial sanding you only sand on the blob, not the surrounding paint is a good safety precaution. If the blob is small enough you can even cut a hole into the center of a wide piece of painter's tape and then just place the single piece of tape right over the blob.

After you knock down most of the blob you will have to take the tape off and do your finish sanding without it...

Unless the blob is very tall the tape idea probably won't work with the Unigrit block.


Dress the Unigrit Block
If you use the Unigrit block, sand the edges smooth and knock the corners down you don't gouge your paint. For a blob you might try standing the block on end and either sanding back and forth, or twisting right top of the blob with the non-painted end of the Unigrit Block. Rinse often.


Blending or Feathering...
After you get it knocked down to where it's pretty flat then do a little blending of the edges of the blob and the surrounding paint, you want to make sure there's no raised edges...

If you do some cover passes with your highest grit paper, #3000 to #4000 if you have it...


Rubbing
Then start rubbing with some M105 or UC and remove your sanding marks, might start out with a microfiber applicator or a terry cloth applicator for a little extra bite and then switch over to a foam applicator pad.


Rock Hard and Desert Dry
As for waiting time... you really want the paint dry and hardened-up. If the paint is still soft it will be rubbery and when you do to buff out your sanding marks, by hand or machine, what will usually happen is the heat and the rubbing will pull the touch-up paint right out of the chipped area and you'll be back to square one only with less paint surrounding the chipped area.

 

[CEE DOG]

Re: Need your suggestions - Final steps in a chip repair

Super glue a small round piece of the sandpaper to the back of a pencil (the eraser side). I haven't tried this yet but got the tip from Richy if I recall correctly.

 

[Mike PhillipsMike Phillips is verified member.]

Re: Need your suggestions - Final steps in a chip repair

Super glue a small round piece of the sandpaper to the back of a pencil (the eraser side).

I haven't tried this yet but got the tip from Richy if I recall correctly.

I'm the last person to claim someone else's idea as my own, but here's an instance where I had a similar idea but have never tried it. In keeping with the saying,

"You don't know what you can do until you try"

• Take a hole punch, punch out some holes in some sandpaper.

• Cut a pencil down to about 2-3 inches long on the erasure side.

• Glue these onto the face of an unused pencil erasure.

• Place the pencil in a Drill.

• Carefully hold the drill in such a way to sand on top of a rock chip.

The goal is to take a ragged random shaped rock chip and turn it into a perfect circle with an even impression in the paint and now sanded clean for good adhesion.

Then apply your touch-up paint till the hole is level.

Allow to dry for about a week or two in warm temperatures.

Carefully sand the touch-up paint flat.

Remove sanding marks.


I'll give it a try on my Jimmy after the glue has dried that's holding the #1000 Grit Sandpaper to the Pencil Erasure.

I think a lower grit would actually work better, like #600 or #800 but #1000 is as low as I had at my desk.

 

[tguil]

Re: Need your suggestions - Final steps in a chip repair

Mike,

Thanks for your "specific" reply. Yep, I read all of your posts over on MOL, including the warnings. I've had the Unigrit blocks for several years but have not used them. Most to the time I do not use the "blob technique" on chip repair so I have had no occasion to use the blocks. My usual procedure is to carefully fill the chip level with the surface of the original surface and by thinning the paint with extreme patience I come darn close. Then I gently message it a bit with fine Nikkens paper and buff it. This particular chip is on a vertical surface so "blobs happen". When the "blob" started I figured what the heck, might as well make it a real "blob". The fender that I am working on was bead blasted and then repainted. The painter applied a ton of clear so I should be OK with the sanding

Yesterday I did some chip touch-ups on both my wife's Tacoma and my Ram. No "blobs" and no hassle.

Thanks for your comments and with the additions to what you have said previously, you might want to refer you "perfectionist friends" to this thread. Very good information.

Tom

 

[CEE DOG]

Re: Need your suggestions - Final steps in a chip repair

I'm the last person to claim someone else's idea as my own, but here's an instance where I had a similar idea but have never tried it. In keeping with the saying,

"You don't know what you can do until you try"

• Take a hole punch, punch out some holes in some sandpaper.

• Cut a pencil down to about 2-3 inches long on the erasure side.

• Glue these onto the face of an unused pencil erasure.

• Place the pencil in a Drill.

• Carefully hold the drill in such a way to sand on top of a rock chip.

The goal is to take a ragged random shaped rock chip and turn it into a perfect circle with an even impression in the paint and now sanded clean for good adhesion.

Then apply your touch-up paint till the hole is level.

Allow to dry for about a week or two in warm temperatures.

Carefully sand the touch-up paint flat.

Remove sanding marks.


I'll give it a try on my Jimmy after the glue has dried that's holding the #1000 Grit Sandpaper to the Pencil Erasure.

I think a lower grit would actually work better, like #600 or #800 but #1000 is as low as I had at my desk.

Nice, I like it! :dblthumb2:

 

[tguil]

Re: Need your suggestions - Final steps in a chip repair

"Rock Hard and Desert Dry"? If you really want to be sure that the paint is thoroughly dry, would there be any advantage to not only wait a week to start the sanding, but also actually do the sanding in a over a couple of days taking a little at a time. This touch up is a heck of a lot thicker than a spray job. And to think I've already taken the "cure " for "OCDD" (obsessive compulsive detailing disorder).

Tom

 

[tguil]

Re: Need your suggestions - Final steps in a chip repair

Finished the touch-up today following Mike's suggestions for the Unigrit Blocks. The touch-up came out almost perfect. (In other words, I can still see a bit of my work using my reading glass when I am in the "right" light ) A so-so camera and black paint won't show much of anything. The Unigrit Blocks are definitively worth the "bucks" for this type of touch-up.

I really took my time on this little repair. Almost a week to layer in the paint and then I let the paint cure for another week before tackling the "blob".

Thanks for the advice, Mike.

Tom

 

[Mike PhillipsMike Phillips is verified member.]

Re: Need your suggestions - Final steps in a chip repair

Time stamp of the below post

09-07-2010, 10:20 AM

I'm the last person to claim someone else's idea as my own, but here's an instance where I had a similar idea but have never tried it. In keeping with the saying,

"You don't know what you can do until you try"

• Take a hole punch, punch out some holes in some sandpaper.

• Cut a pencil down to about 2-3 inches long on the erasure side.

• Glue these onto the face of an unused pencil erasure.

• Place the pencil in a Drill.

• Carefully hold the drill in such a way to sand on top of a rock chip.

The goal is to take a ragged random shaped rock chip and turn it into a perfect circle with an even impression in the paint and now sanded clean for good adhesion.

Then apply your touch-up paint till the hole is level.

Allow to dry for about a week or two in warm temperatures.

Carefully sand the touch-up paint flat.

Remove sanding marks.


I'll give it a try on my Jimmy after the glue has dried that's holding the #1000 Grit Sandpaper to the Pencil Erasure.

I think a lower grit would actually work better, like #600 or #800 but #1000 is as low as I had at my desk.

Have a new article on this on the way...