Paint touch up question

[JohnnyO]

Just brought the shell back home after getting the body work done and engine bay sprayed in single stage and noticed a couple of small runs. I won't be bringing the car back to get topcoated until March and wanted to address the runs before I drop the motor back in.

Can I just sand these runs down and recoat with single stage or is there more to it?

What grit should I use?

Should they be wet sanded then dried with a heat gun?

If I repaint it is there a posibility of it wrinkling on me?

I do have enough paint to spray the entire engine bay a few times over.

Any pro's out there that can offer some advice?

TIA,

John

[geezer]

Wet sanding is the method I would use, especially on fresh paint. Sometimes it can be very difficult to sand out a run in fresh paint without it "digging out". Use at least as fine as a 600 grit, use a small rubber block or at least keep good control of the paper, keeping it flat with light pressure. Don't continue to use clogged or dull paper. I know nothing about the paint you used or the "blendability" of spot repairs using it. Experiment with it in an inconspicuous spot. Make sure the paint has cured enough before doing anything. If you have enough to do a complete repaint, you can lightly wet sand the entire bay and respray it, eliminating any blending concerns. Or, it could be that a repaint of the entire engine bay is unnessesary and you can take advantage of character lines, seams or other natural breaks, making it easy to blend in. Underhood color matching should be much less of a problem.

Edited December 24, 2009 by geezer

[JohnnyO]

Thanks Ron, That is exactly the what I needed to know. I was pretty sure that it could be done just wasnt sure how.

Appreciate the help.

Merry Christmas...

John

[palosfv3]

Careful trying to remove runs. The location of the run , color and type of paint will have a significant influence on the method used to correct the problem. Understanding when the run occured is critical to selecting the correct repair process. Is the run in the sealer , Base color or clearcoat ? If your dealing with a run that is in the clearcoat or the topcoat of a solid single stage color , you stand a good chance of removing it without too much trouble. If the run is in the sealer, base color or a hi-metallic single stage color ( silver as an example ) you will probably be better off blending in or respraying the problem area. We use run removal method that takes a little practice and is not for the faint of heart. Taking a new single edged razor blade lightly pull the blade perpendicular and lengthwise across the run ( pay attention to the edge of the razor blade it can easily dig into the concave areas of the panel adjacent to the run). This will level the run better than the sanding block. Once completed lightly block the area with 1500 and buff. Removing runs takes some practice to get right . Some runs no matter how much you would like to try to save the panel must be repainted. The best rule of thumb is if you cant repair the run in 15/ 20 minutes refinsh the area .

[JohnnyO]

Larry,

Thanks for the tip. I might give it a shot. One of the 2 runs I noticed are under where the Master Cylinder goes so it won't be noticable when the car is assembled but I want it perfect.

It is single stage paint that has been curing for about 10 days now. Might still be soft. I am pretty sure that the run is in the top coat not the surfacer. As stated above, I do have enough SS to repaint the entire engine bay if needed.

Thanks again.

John

[kzim81]

John: Depending how big the runs are, if they are small start out with 1000 to 1200 grit wet, if you have a straight block I even use a wooden mixing stick "cut it down" 4" carefully like you are planning a piece of wood. Another option take a new razor blade between your fingers slight angle like you are standing the blade up on the edge light pressure drag the edge over the run like this the back slash as your blade ( \ ) moving to the left.

If the runs are large carefully start with 600 to 800 wet than finish off with 1500 to polish. Hope this helps

Just brought the shell back home after getting the body work done and engine bay sprayed in single stage and noticed a couple of small runs. I won't be bringing the car back to get topcoated until March and wanted to address the runs before I drop the motor back in.

Can I just sand these runs down and recoat with single stage or is there more to it?

What grit should I use?

Should they be wet sanded then dried with a heat gun?

If I repaint it is there a posibility of it wrinkling on me?

I do have enough paint to spray the entire engine bay a few times over.

Any pro's out there that can offer some advice?

TIA' date='

John[/quote']

[tlorber]

My understanding is that you should give it at least a couple weeks before you sand it out. If you use a fine enough grit for a final, you should not need to reshoot the color coat. If you are going to top coat it (by that I assume you mean clear coat) I would be resistant to using a compound after sanding. The clear coat may not adhere to that area.

[JohnnyO]

I will be working on this tomorrow. The paint is now about 4 weeks old so I gather I should be safe to sand and try the razor method mentioned above. The area is in the engine bay on the fender well where the brake booster and clutch slave attach so it is not very visible after assembly but I want it right.

The paint is single stage. I will scuff the entire area with 600 and repaint when I get the runs out.

I will let you know how it goes.

John

[AZ-240z]

John,

Just my take on everything I have read, so far, in this thread. I would forget about the razor blade, (too much of a chance of gouging the paint) and just use fine paper on a very small hard rubber block. I would, initially, mast off the drip and sand the bulk of the run, then remove the masking tape and try to cut it down to match the rest of the painted surface. Then use something like a 3M polishing compound. I think you can achieve perfection without the trouble and headaches of trying to blend in touchup paint. I have done this many times and, when done, cannot find the runs I worked on.

Dan

[DeesZ]

AZ-240z related my exact thoughts on a remedy. IMHO it is least invasive and provides some protection to the surrounding area. I have had success using this method also.

[JohnnyO]

Thanks Dan and John. Like I said, I will tackle this tomorrow on my day off (Government worker!)

I did find another area in the bay that was a little thin and I might just mask off that entire area after I sand down the runs and give the whole area a couple coats after hitting it with 600 grit.

I do have the remainder of the paint, hardener and reducer which is more than enough to do the job right.

I will let everyone know how it turns out.

John