[75sprintguy]

i just painted my car with some ppg gloss black enamel its nice in most places
but i found some runs in my job and a few fish eyes this is my first coat
can i just let it cure and dry then sand them out and recoat or is there
another way. i also used wet look hardner please help a newbie painter thanks

[powerrodsmike]

I am no painter, (but I've squirted some paint).

I have had really good luck sanding runs out with one of these.


http://www.meguiars.com/?pro-blocks/Sanding-Blocks

I don't know if it'll work with the enamel though.



Later, mikey

[jcclark]

The main challenge with run removal is to get the run hard enough
to sand and buff, not just hard enough but as hard as the surrounding paint.
Runs stay softer than the surrounding paint because of their thickness,
so they sand and buff differently, that is why it's hard to remove the
ghost image of it.
For urethanes, you can sand it just less than flush, let it age a day
or two then finish, that helps a lot, cutting the thickness first so it
can catch up with the surrounding paint in hardness.

For enamel, it may never harden enough, but cutting the thickness first
really helps. Do that then sit it in the sun or a heat lamp.
The longer you wait, the better it should do.
Try denting it with the edge of your fingernail for a hardness test.
You'll be surprised how long you can do that with enamel.

[milo]

This is the best thread I've seen here in a long time and it's only 3 or 4 posts long...

It's been my experience with an ocassional fisheye to sand it half way out or flat before recoating so it will stay sealed and held down so to speak and not reappear...

As for the sanding blocks link by Powderodsmike, I'm about to order one and wonder is 1000 the grit you use most often givin a choice??

JC's point about runs being a bit softer than the rest for a while is right on,, latley I have practiced sanding before buffing with 1000 grit and then letting the sanded "opened" surface breath/gas out for another day before resanding with 2000 and then useing the buffing wheel. It seems as though they stay glossy better if givin time between operations if practical.

[powerrodsmike]

Originally Posted by milo

is 1000 the grit you use most often givin a choice??

JC's point about runs being a bit softer than the rest for a while is right on,, latley I have practiced sanding before buffing with 1000 grit and then letting the sanded "opened" surface breath/gas out for another day before resanding with 2000 and then useing the buffing wheel. It seems as though they stay glossy better if givin time between operations if practical.

I bought a 1500 and it seems to cut really well despite it being so fine a grit..( for a long time I never even knew that there was anything finer than 600 )

I have only used the block on some single stage urethane, and some industrial polyester. (Poly-lux) It worked equally good on nibs.


jcclark, I noticed that about runs being softer in urethane and also it seemed like once I sanded into the run, and broke the surface, the paint underneath was very porous. I thought that one reason you see the ghost image of the run was as a result of the pores holding some of the buffing compound after buffing.

Polyesters get hard throughout, but are still porous in the area under the run. I would guess that is because the thicker paint doesn't have a chance to gas off once it skins.

Later, mikey

[milo]

Thought provoking .. . ...
It's tough to see in the package though I wonder if a block could be cut down in size to that of a sugar cube simalar to the metal nib file in order to keep to a confined area . A concern is how sharp the edge is. I've been toying with the idea of a small dremal type grind stone mounted on a electric tooth brush however that project is still in R&D...(as we read))..

Heres a couple pics . The second one shows a bit of flexable wire insulator in this mockup used to allow the stone "float" on top of a nib..In this test water (spit) is being used as well.

Heres a link to show a metal nib file again in different grits,

http://www.google.com/products?hl=en...&um=1&ie=UTF-8

The metal won't help fisheyes though sometimes they can help with runs.

keeping the tools/paper flat and backed up is key even at the micro level,
using a finger or a rubber block or paintstick behind paper will flex to much when in a tight pinpoint spot etc..
The stone will hold it's shape and has a future ...







Check the thumbnail (pun not intended)

[jcclark]

There are a lot of ways people attack runs. (flow indicators)

Some let it harden and level by scraping with a razor blade on end.
It has to be hardened to work, but it does work pretty good
for initial leveling.

I've heard of applying spot putty around the area before sanding,
kind of like a guide coat to protect the surrounding area.
Then sand till everything is gone.
(I haven't tried that one)

I like sanding with a hard block, I use a small section of a wooden 2x4
that I flatten before useing. I usually coarse sand first, 400 to 600 grit.
Then allow some time to harden and follow up sanding/buffing
as usual.

[Rag top bird]

You should be fine the way I get runs out is take a paint paddle cut off a 2 inch long piece then wrap it with 800 wet sand paper then spray the run with in this case flat white spray paint 1 light coat then block until all the white is gone I like the paint paddle because its not as hard on the edges and doesnt dig into the run