Paint sag... best way to sand out???

studiog · 01-02-05, 08:38 AM

I have a couple of paint sags I need to wet sand out and wondering if anyone might have recommended grits to step up from 320 which is what I started with to knock down the sags. I am still high with the sag but want to start switching to finer paper before I become level with the surrounding paint. Thanks as always guys for any help.

paintdaddy · 01-02-05, 09:37 AM

It depends on how bad the sag is .Im not afraid to admit I had some nice ones this week and had to start off with 400 then 600 then 100 then 1500.Only do this if you have alot of paint to work with.I had 4 good coats of clear but it was still nerve racking.Try that but dont be shocked if you sand through,it happens to the best of us.

studiog · 01-02-05, 09:49 AM

Quote:

Originally Posted by paintdaddy

It depends on how bad the sag is .Im not afraid to admit I had some nice ones this week and had to start off with 400 then 600 then 100 then 1500.Only do this if you have alot of paint to work with.I had 4 good coats of clear but it was still nerve racking.Try that but dont be shocked if you sand through,it happens to the best of us.

I should have mentioned that I have about 6 coats of single stage urethane. I painted a few extra coats just for insurance. If I go through it is not the end of the world as I am still in paint mode and can reshoot the panel. Thanks for the help.

Sting Ray · 01-02-05, 10:27 AM

Next question is was it too much paint that caused the curtains, or did the paint get cold like someone opened a door and it sagged, if the paint got cold it might all have a sag, and you would have to repaint the area.

Tom

61 Silver · 01-02-05, 10:48 AM

Paintdaddy

Have you ever tried to dry scrape with a razor blade? I have done it on furniture that was sprayed with lacquer, but never tried it with an auto finish.

Ray

studiog · 01-02-05, 12:28 PM

Quote:

Originally Posted by sting66ray

Next question is was it too much paint that caused the curtains, or did the paint get cold like someone opened a door and it sagged, if the paint got cold it might all have a sag, and you would have to repaint the area.

Tom

Tom,

I layed one more coat on what already had 4-5 coats under it. I just got carried away with too much paint in one area.

John Mcgraw · 01-02-05, 12:43 PM

Studiodog,

I have a couple of tools that are real handy for removing runs. The first is called a run razor, and it is a single edge razor blade that has a base that slides along the panel and has a micrometer adjustment knob that lowers the blade to shave away the run. The other tools are called nib files. These are small pieces of a vixen file that are attached to a wood back block they are about 1.5" square and ae very easy to shave down small runs. Vixen files have curved teeth and only cut in one direction, so you just stroke the file over the surface until it shaves the high spot down to flat. When you are sanding, allways use a very firm block to flatten the run. A softer block will cut the area around the run as well and you take the chance of sanding through before the run is gone.
I will usually use a small block of aluminum under my sandpaper to assure that I only cut the run. The smaller the block, the less likely you will sand area arround the run. You can get the runrazor and nib files at most body supply stores, and I believe that I saw them in Eastwood's catalog, but I couldn't swear to it.
Regards, John McGraw

studiog · 01-02-05, 10:08 PM

Quote:

Originally Posted by John Mcgraw

Studiodog,

I have a couple of tools that are real handy for removing runs. The first is called a run razor, and it is a single edge razor blade that has a base that slides along the panel and has a micrometer adjustment knob that lowers the blade to shave away the run. The other tools are called nib files. These are small pieces of a vixen file that are attached to a wood back block they are about 1.5" square and ae very easy to shave down small runs. Vixen files have curved teeth and only cut in one direction, so you just stroke the file over the surface until it shaves the high spot down to flat. When you are sanding, allways use a very firm block to flatten the run. A softer block will cut the area around the run as well and you take the chance of sanding through before the run is gone.
I will usually use a small block of aluminum under my sandpaper to assure that I only cut the run. The smaller the block, the less likely you will sand area arround the run. You can get the runrazor and nib files at most body supply stores, and I believe that I saw them in Eastwood's catalog, but I couldn't swear to it.
Regards, John McGraw

Thanks John,
That is very helpful info and very handy tools. I think I will start with Eastwood to see if they have both of tose items. Is it best to use the razor tool when the paint is still soft or can it be used at any time? Does it work on curved surfaces. Thanks again.

John Mcgraw · 01-02-05, 10:38 PM

You can use the run razor on cured paint, but is works a lot easier on softer paint. If you don't have a lot of runs, you may just want to block the runs out with an aluminum block. It will probably take a week to get the tools from Eastwood. The run razor will work on flat or curved panels. The DCC product is pretty forgiving, but painting with the wrong reducer for the ambient temp can cause it to really sag. I shot some last week, and all I had in the cabinet was some DT885, and It was tough to keep it from running! This reducer is more applicable for 90 degree weather than 50 degree!

Regards, John McGraw

studiog · 01-02-05, 11:02 PM

Quote:

Originally Posted by John Mcgraw

You can use the run razor on cured paint, but is works a lot easier on softer paint. If you don't have a lot of runs, you may just want to block the runs out with an aluminum block. It will probably take a week to get the tools from Eastwood. The run razor will work on flat or curved panels. The DCC product is pretty forgiving, but painting with the wrong reducer for the ambient temp can cause it to really sag. I shot some last week, and all I had in the cabinet was some DT885, and It was tough to keep it from running! This reducer is more applicable for 90 degree weather than 50 degree!

Regards, John McGraw

I had one area that had allot of runs but I have already block sanded and I decided to repainted it tonight. It looks great now. Now I only have 2 minor sags left so I think I will block them out with the aluminium block as you suggested. I used a medium reducer as it was suggested by dealer, but knowing what I know now I wish I had gotten the faster reducer.

Tom Bryant · 01-03-05, 11:58 AM

Eastwood has the Nib files and I think they may have the razor too. I'd check your local paint store first since you can get them right now and without shipping. They may be cheaper too. Although I buy stuff rom Eastwood regularly they are not a discount catalog. I always shop their prices elsewhere.

Tom

studiog · 01-03-05, 04:54 PM

Quote:

Originally Posted by Tom Bryant

Eastwood has the Nib files and I think they may have the razor too. I'd check your local paint store first since you can get them right now and without shipping. They may be cheaper too. Although I buy stuff rom Eastwood regularly they are not a discount catalog. I always shop their prices elsewhere.

Tom

Thanks much Tom.