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Old 04-02-2013, 08:14 PM
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spot repair

hi I need some tips on how best to do a small spot repair on a classic car. the car was repainted in 94 and it has what looks an acrylic urethane single stage metallic factory color on it. still looks nice and shiny other than the scratch. the previous owner doesn't remember but thinks it might have been deltron.
I know it would be best to do the whole quarter but i want to attempt to spot repair it because there is no line to break the quarter and it has expensive graphics on it.
that being said what is the best way to attempt it? how well do the blending agents work? what about using bc cc for the spot repair and then color sand and buff?

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Old 04-03-2013, 03:57 AM
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If it's Deltron, your probably in luck...and it would make sense seeing that you have expensive graphics on your car. Deltron is one of PPG's base coat/clear coat products. Also you mentioned that it "still looks nice and shiny other than the scratch", if it was Acrylic Urethane and a metallic, chances are it wouldn't be that shiny...Metallic Single Stage paints are generally not very shiny unless it has a very low amount of metallic in the paint. The way you can check to see if it's BC/CC is to take a piece of sand paper (try 600 grit) and on an inconspicuous area, preferably a dark color and gently sand the area (close to where the scratch is would work as well, it needs to be repaired anyway) and check the grit side of the sandpaper for color...if the sanding dust is white, you have base clear, if the sanding dust is the color of what you sanded, it's single stage.

As I mentioned, because you have graphics and it's been suggested that it's PPG's Deltron, the paint will most likely be Base Coat/Clear Coat...do you have formulas for the color that your trying to repair? Would it be possible to post pictures of the scratched area and the graphics? If the scratch is close to the graphics it may be a very involved repair and might be a candidate for a "don't try this at home" scenario.

If you could answer these few questions and try to post several pictures, I will try and advise you as to the best ways to repair your scratch.

Ray
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Old 04-03-2013, 06:37 AM
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I did the sand test. its single stage. I wish it was base coat. I have some experience with those. the paint is the gm factory color so the formula should be available. it is metallic but the metallic is barely visible.
I can blend it in but I am looking for tips on getting it as undetectable as possible.
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Originally Posted by 69 widetrack View Post
If it's Deltron, your probably in luck...and it would make sense seeing that you have expensive graphics on your car. Deltron is one of PPG's base coat/clear coat products. Also you mentioned that it "still looks nice and shiny other than the scratch", if it was Acrylic Urethane and a metallic, chances are it wouldn't be that shiny...Metallic Single Stage paints are generally not very shiny unless it has a very low amount of metallic in the paint. The way you can check to see if it's BC/CC is to take a piece of sand paper (try 600 grit) and on an inconspicuous area, preferably a dark color and gently sand the area (close to where the scratch is would work as well, it needs to be repaired anyway) and check the grit side of the sandpaper for color...if the sanding dust is white, you have base clear, if the sanding dust is the color of what you sanded, it's single stage.

As I mentioned, because you have graphics and it's been suggested that it's PPG's Deltron, the paint will most likely be Base Coat/Clear Coat...do you have formulas for the color that your trying to repair? Would it be possible to post pictures of the scratched area and the graphics? If the scratch is close to the graphics it may be a very involved repair and might be a candidate for a "don't try this at home" scenario.

If you could answer these few questions and try to post several pictures, I will try and advise you as to the best ways to repair your scratch.

Ray
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Old 04-03-2013, 07:12 AM
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What color is it that has the scratch...is it dark or light...also do the graphics go from one end of the quarter to the other end? Again if you would give me a bit more information and if possible post pictures, I will do my best to give you some tips...even though Acrylic Urethane is much harder to blend than BC/CC or even Acrylic Enamel.

Ray
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Old 04-03-2013, 07:25 AM
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Quote:
Originally Posted by 69 widetrack View Post
What color is it that has the scratch...is it dark or light...also do the graphics go from one end of the quarter to the other end? Again if you would give me a bit more information and if possible post pictures, I will do my best to give you some tips...even though Acrylic Urethane is much harder to blend than BC/CC or even Acrylic Enamel.

Ray
don't have a pic right now. the color is a dark maroon. the graphics go most of the length of the quarter but not all the way to the end so there is no line to tape to.
the graphics are about 15 inches from the actual repair but are not involved in the repair. they only enter into the repair by the fact that if I did the whole quarter I would have to destroy them.

I have found some info on a product called Sherwin-Williams products BS10. it is supposed to help blend repairs. don't know how it works though.
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Old 04-03-2013, 07:37 AM
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just found some deltron specific info:


http://www.bapspaint.com/docs/psheet...tron/P-235.pdf
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Old 04-03-2013, 09:31 AM
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OK the DX840 is PPG's blending solvent and it's a very good idea to use the blending solvent from the same manufacturer that you get your paint from. Blending solvent is basically a very slow reducer (it does have other properties in it that give the paint more teeth to bite into the existing finish).

If your going to use PPG, the Acrylic Urethane is called Concept (I'm from Canada and I don't know if in the US they called the Acrylic Urethane Deltron Concept or just Concept). As I'm sure you are aware, you will need to first repair the scratch (if you need information on this let me know and I will try and walk you through the steps involved). After you have filled the scratch the trick is to keep your repair area small without any hard masked primer lines. The best way to achieve this is to take a piece of masking paper with masking tape on it and basically lay the masking paper down allowing the paper to cover up the repair and then lift it up so that the repair is exposed (about 2 inches on all sides of the repaired scratch). By reverse masking you will create a soft edge and when you apply 2 coats of primer, there won't be a solid line of primer that you need to sand off. After it's been primed and the primer has cured use a small block and prep the area that has been primed with 400 grit dry or 600 grit wet paper...I prefer 600 grit wet, it's seems to leave a better finish.

Now you have your repair complete reverse mask the graphics about 1 inch away from the graphics (the same way as you did for primer) this, if your scratch was 15 inches away from the graphics, less the 1 inch you reverse masked at the graphics and the 2 inches you applied primer on the scratch, should give you 12 inches to do your blend. Prep the area around the scratch with a white 3M Scotch Brite pad all the way up to the masking paper protecting your graphics and 12 inches below and 12 inches on both sides of the repaired scratch. Mix up a small amount of paint with the proper hardner and reducers outlined in the tech sheets. Now you will need to set up your paint gun to paint a small area, turn your fan in so that you have about a 2 to 2 1/2 inch pattern, also turn your volume of paint down and adjust your air pressure so you are spraying at the recommended pressure. If you have 2 paint guns, that would be a benefit now, one for paint one for blending solvent...if you don't...apply the paint until you have coverage and allow it to flash between coats, immediately after you have achieved hiding, remove about 50% of the paint in your gun and replace it with DX840 blending solvent, stir the paint with the blending solvent thoroughly put it back in the paint gun and purge the gun (you will still have 100% catalyzed paint in the chamber of the gun which you can remove by triggering the gun or purging...just like nitrous). Now open your pattern up so that you have a 3 to 3 2/3 inch fan, check and adjust your air pressure, your volume should remain about the same because with the blending solvent your thinning or lowering the viscosity of the paint and apply this solution around the area you have just painted...again, remove 50% of the paint and blending solution in your gun, replace what you have removed with blending solvent and apply another coat extending each coat past the last and repeat until the entire prepped area has been painted, do not apply paint past the prepped area...it will have a tendency to peel. If you find that any area of the blend is getting dry, apply a coat over that or the entire area to keep it wet and maintain gloss. When the entire prepped area is covered you are done, remove the masking paper and allow it to cure, once it has cured thoroughly you may compound and buff (I prefer to hand polish...less chance of the fresh paint peeling back). If you did everything correctly, you should have an invisible repair.

Now, I do need to mention, doing a blend in clear coat is difficult, doing a blend in Acrylic Enamel can also be very challenging...doing a blend in Acrylic Urethane is even more difficult than either of the other 2 products, it takes a lot of practice and knowing exactly when and how to apply the products and many professionals have trouble blending, let alone a metallic Acrylic Urethane.

I hope this helps, if you need more information, let me know and I'll try and be more clear, or, if you have access to two paint guns, I can outline the two gun method for you (I personally have had more success with the two gun method when blending Acrylic Urethane than with the one gun method).

Ray
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Old 04-03-2013, 09:42 AM
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thanks for info. I will give it a try. I do have several guns. even a mini gun for blending.
Quote:
Originally Posted by 69 widetrack View Post
OK the DX840 is PPG's blending solvent and it's a very good idea to use the blending solvent from the same manufacturer that you get your paint from. Blending solvent is basically a very slow reducer (it does have other properties in it that give the paint more teeth to bite into the existing finish).

If your going to use PPG, the Acrylic Urethane is called Concept (I'm from Canada and I don't know if in the US they called the Acrylic Urethane Deltron Concept or just Concept). As I'm sure you are aware, you will need to first repair the scratch (if you need information on this let me know and I will try and walk you through the steps involved). After you have filled the scratch the trick is to keep your repair area small without any hard masked primer lines. The best way to achieve this is to take a piece of masking paper with masking tape on it and basically lay the masking paper down allowing the paper to cover up the repair and then lift it up so that the repair is exposed (about 2 inches on all sides of the repaired scratch). By reverse masking you will create a soft edge and when you apply 2 coats of primer, there won't be a solid line of primer that you need to sand off. After it's been primed and the primer has cured use a small block and prep the area that has been primed with 400 grit dry or 600 grit wet paper...I prefer 600 grit wet, it's seems to leave a better finish.

Now you have your repair complete reverse mask the graphics about 1 inch away from the graphics (the same way as you did for primer) this, if your scratch was 15 inches away from the graphics, less the 1 inch you reverse masked at the graphics and the 2 inches you applied primer on the scratch, should give you 12 inches to do your blend. Prep the area around the scratch with a white 3M Scotch Brite pad all the way up to the masking paper protecting your graphics and 12 inches below and 12 inches on both sides of the repaired scratch. Mix up a small amount of paint with the proper hardner and reducers outlined in the tech sheets. Now you will need to set up your paint gun to paint a small area, turn your fan in so that you have about a 2 to 2 1/2 inch pattern, also turn your volume of paint down and adjust your air pressure so you are spraying at the recommended pressure. If you have 2 paint guns, that would be a benefit now, one for paint one for blending solvent...if you don't...apply the paint until you have coverage and allow it to flash between coats, immediately after you have achieved hiding, remove about 50% of the paint in your gun and replace it with DX840 blending solvent, stir the paint with the blending solvent thoroughly put it back in the paint gun and purge the gun (you will still have 100% catalyzed paint in the chamber of the gun which you can remove by triggering the gun or purging...just like nitrous). Now open your pattern up so that you have a 3 to 3 2/3 inch fan, check and adjust your air pressure, your volume should remain about the same because with the blending solvent your thinning or lowering the viscosity of the paint and apply this solution around the area you have just painted...again, remove 50% of the paint and blending solution in your gun, replace what you have removed with blending solvent and apply another coat extending each coat past the last and repeat until the entire prepped area has been painted, do not apply paint past the prepped area...it will have a tendency to peel. If you find that any area of the blend is getting dry, apply a coat over that or the entire area to keep it wet and maintain gloss. When the entire prepped area is covered you are done, remove the masking paper and allow it to cure, once it has cured thoroughly you may compound and buff (I prefer to hand polish...less chance of the fresh paint peeling back). If you did everything correctly, you should have an invisible repair.

Now, I do need to mention, doing a blend in clear coat is difficult, doing a blend in Acrylic Enamel can also be very challenging...doing a blend in Acrylic Urethane is even more difficult than either of the other 2 products, it takes a lot of practice and knowing exactly when and how to apply the products and many professionals have trouble blending, let alone a metallic Acrylic Urethane.

I hope this helps, if you need more information, let me know and I'll try and be more clear, or, if you have access to two paint guns, I can outline the two gun method for you (I personally have had more success with the two gun method when blending Acrylic Urethane than with the one gun method).

Ray

Last edited by vhehn; 04-03-2013 at 10:05 AM.
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Old 04-03-2013, 10:01 AM
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Excellent post Ray. I think a lot of us would be interested in a good explanation of the two gun method if you don't mind.

I have muddled through a couple of blends with mixed results.

John
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Old 04-03-2013, 10:15 AM
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I think you should call the painter who painted it. Blending a single stage metallic isn't easy, let alone knowing the fact there's graphics right next to it. tell us how it comes out, this one will be interesting.

Most shops do not blend single stage metallics cause it can be difficult and not worth the trouble. That should tell you something there.

Last edited by tech69; 04-03-2013 at 10:24 AM.
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Old 04-03-2013, 10:31 AM
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not possible. the car was repainted in 1994. everybody involved has moved on by now.

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I think you should call the painter who painted it. Blending a single stage metallic isn't easy, let alone knowing the fact there's graphics right next to it. tell us how it comes out, this one will be interesting.

Most shops do not blend single stage metallics cause it can be difficult and not worth the trouble. That should tell you something there.
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Old 04-03-2013, 10:32 AM
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Pictures would help a lot. I would do the repair in base/clear. This would allow for easy color blending. You could use the graphics to cut it off and find the smallest area to complete the clear blend.
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Old 04-03-2013, 10:44 AM
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Yep. he could even do a spray out card with a flattener added to the clear to get the right gloss, or un-gloss.

I really like Ray's post though.
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Old 04-03-2013, 11:02 AM
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Blending is almost an art form John, mixed results are very common. I remember the first clear blend I did on a C pillar that I didn't need to polish...I thought I had it mastered...until the next one I did...LOL.

I've had the benefit of working with a number of shops through out my career and unlike working in one shop (which does have benefits as well) I worked with numerous shops and was able to learn from many technicians...and very quickly you learn the good techniques from the bad...there's plenty of them as well.

One shop I dealt with in particular, all they did was spot repairs...and did quite well doing it. If you had a ding in your bumper cover, that would cost about $250, (a body shop would charge between $500 and $600 to repair and paint a cover flat rate)...if you had another ding in your fender and it was the same color, that would cost about $150, they averaged 8 to 10 cars a day, so the painter needed to be damn good at blending clear's and single stage. They used every technique, every piece of equipment that would speed up production like UV Primer that cured in a matter of minutes, fast clears with infrared heat lamps every where...it was quite a sight to see and I will say, I did learn a lot from that painter and the other people working in that shop as well.

OKay, when you use the two gun method the prep is the same, again, reverse masking (I hope I explained that well enough in my previous post) is very important. As with one gun, apply paint over the repaired, primed area (just as before, if it's a scratch that your repairing, dial your gun in so that your fan, volume and air pressure are sufficient to cover the primed area). Once you have coverage with allowing proper flash times between coats, remove 50% of the paint in your gun, replace it with blending solvent and purge the gun. With the other gun, put straight blending solvent into the pot and mist a coat of blending solvent over the prepped area, with the other gun, mist a coat of 50% catalyzed paint/50% blending solvent several inches past the area that you have just achieved coverage...allow some flash time, just enough so that the blending solvent has started to evaporate and you can visually see your prepped edge. Again, mist blending solvent over the entire prepped edge. Leave the 50/50 solution in gun #1 and immediately mist on another coat of the 50/50 solution stepping it just a little further than the last pass, even less flash, repeat a mist coat of blending solvent followed by an immediate pass with the 50/50 solution. The reason I don't add more blending solvent to the material in gun #1 is that I have the extra blending solvent already sitting on my prepped area that I haven't allowed to totally flash. There are instances where I would add more blending solvent to my paint, even with the two gun method, those would be colors with a high metallic content or if I'm blending larger areas, blending solvent flashes a lot slower than any reducer and that way on a large blend I can keep a wet edge). Repeat until the prepped area has been covered (or very close to completely covered...the over spray should melt into the remaining small area). Allow it to cure, hand polish if needed (chances are on Single Stage you will need to hand polish) and the repair should be invisible. I hope I have explained this well enough, if you or anyone else has any questions, just ask and I'll try and be more clear.

One reason I like the two gun method better for Single Stage and clear blends over a large area is that you have more control of the amount of blending solvent, if you have a dry edge you can mist on blending solvent and the dry edge goes away and for the fact that Acrylic Urethane's are a Bear to blend, with pure blending solvent being misted on the prepped area, it makes the substrate more conducent to accepting the freshly applied paint and less chance off peeling back.

The painter in the shop I mentioned earlier would average polishing 3% of his jobs (yes, the shop kept track) and about 8% to 10% of the jobs they did where Single Stage. This is what the painter did all day every day and when it came to blending color and clear, I haven't ever seen anyone better. I didn't sell them a lot of toners, a fair amount of clear...but they sure bought more UV primer than any shop I ever had before.

Ray
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Old 04-03-2013, 11:13 AM
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I should mention again that blending is difficult, blending Single Stage is even more difficult, blending Single Stage metallic's are extremely difficult to do and maintain gloss and not leave a dull or dry edge, especially Acrylic and Poly Urethane's. Getting a gloss on Acrylic Urethane's with metallic's is hard to get, that's why many Single Stage colors that have a gloss, don't have much in the way of metallic's or are solid colors. The OP mentioned that the Burgundy color that needs to be repaired was a low metallic color, however, I don't understand why a painter would do graphics and metallic's in Single Stage when BC/CC was readily available in 1994.

Ray
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