• Having site issues? Contact Dub@southernPolyurethanes.com

Spraying Tri-Coat Paint

#1
I have sprayed SS and BC/CC but never Tri-Coat. Somebody scratched and dented the rear driver's side door on my 2011 Ford Expedition EL. Color is white platinum tri-coat. Questions:

What color primer to use? (if it matters) I am thinking gray?

After base coat, how do I know what is too much or not enough inter-coat to blend in with the original paint?

Thanks in advance!
 

Chris_Hamilton

Trying to be the best me, I can be
#2
Repaired and shot that exact color many times over the past few years so I'll tell you what works for me.
1. Do your bodywork. Try to contain the repair area as much as possible. Prime (gray is fine) and sand. Finish sand your bodywork (primed area)with 600 wet. If you have any sand through areas re prime and resand.


2 Prep the adjacent panels, meaning the front DS door and the rear quarter. Remove what you can i.e. the mirror, door handle, etc. On the window moldings if you are in any doubt about being able to remove them without damaging them (it's not hard to damage them) leave them on and do what I call a "pull off". I'll explain that later. After you have as much trim etc. removed as necessary then you can start the prep process. I use 800 grit and flatten the orange peel with a soft block (Motorguard roller block) Idea is to level the factory orange peel somewhat. Sand in a back and forth motion, keeping all your scratches going in one direction. Do not cross hatch, and do not sand haphazardly. When you see it start to flatten that is good enough, stop. Do this on the door your repaired including the primed area (just enough to remove the 600 grit scratches) the DS front door and the DS quarter. Don't worry about small areas or edges those will get scuffed i the next step. Now using a grey 3M scotchbrite pad (kind you get at your paint jobber not hardware store type) use some Presta Scuff Stuff or equivalent (available at your Paint Jobber or online look for "sanding paste") wet your panel and the pad and using the scuff stuff start scuffing all three panels. I tend to go either back and forth with the pad or tight circles whichever suits the situation. Make sure you scuff each panel 100%. Pay extra attention to the edges. Rinse and look for any areas you may have missed. You'll notice a slight difference in how a scuffed only area looks versus one you sanded with 800 looks but don't worry about that. As long as it's scuffed that's all you want. Give the entire vehicle a wash or at the very least a good rinse. Let it dry then you are ready to proceed to the next step.

3. Mask the vehicle, do it in such a way as to try and seal off as much as you can. Meaning for example the wheel opening instead of bagging the wheel, back tape around the perimeter of the opening and mask the entire opening off. Doing this will make for a cleaner job. Don't forget your door jambs. I like to leave just a slight amount untaped so there are no unsightly tape lines in the jamb areas. Nothing looks worse than that. Example when taping a door jamb run the tapeup to the seam where the door skin meets the door, leave that folded over area of the skin untaped. When you untape you'll feel and see no transition. As you are taping if you left the window molding on or the window rubber then you'll need to do a "pull off". Simply tape the car up leaving a small gap where the molding meets the paint. Instead of laying down your tape first to the paint you'll do that last. After you have everything taped up, come back to the moulding and tape it. Being very careful to only tape the molding rubber etc. Extend it out past the end and beginning of whatever you are taping and fold a small bit over at the ends to aid you in pulling it off. After your final coat of clear while it is still wet you can pull it off and you'll have no tape line and no risk of lifting in that area like you would if you waited until everything was dry to untape.

4, If you are still with me:) you are now ready to shoot it. After wiping it down tack it off. Undo your tack and let it glide over the surface, don;t use any pressure. Wipe your paper adjacent to paint down as well. Be very thourough. Don't blow it off at this stage as that actually will cause you to get more trash in it. Car should be clean and blown off before you tape.
If you did as I suggest when you prepped it you will not have to seal it. If you have any sand throughs you'll need to seal it though. I'm going to assume you don't and go from there.
First step is your basecoat. It's simply a solid white. Adjust your gun so you are spraying medium coats. Do not spray heavy coats. I cannot emphasize that enough. Light-medium to medium is all you need to do. First coat spray the primed area concentrating on moving in and moving out at the begining and end of each coat. Describing this is hard for me to put into words. Easier to show someone. You want to momentarily pull the trigger and bring your gun in at the beginning and end of each pass. Doing it this way makes it so there are no discernable stop start areas. Some call this wristing off and on. With your gun hand hold it slightly farther out than where you would spray, slightly squeeze the trigger and pull it in then make your pass pulling out the same way and progressively releasing the trigger. Practice this on some masking paper before you try it on the car.
Extend your passes out with each coat until you have coverage.
Next step is the midcoat, in this case a pearlcoat. You will not use Intercoat, it will come with the basecoat from whomever you get your paint from. Depending on the brand you may or may not need to reduce it. More than likely you will, follow the Manufacturers TDS.
You will spray the pearl the same way as the base. Start your first pass roughly where your basecoat begins and finish where it ends. Left to right or right to left whatever works for you. Extend out with each coat. 2 (usually)to 3(max) coats will be all that's needed. If you want to be assured of a nice transition, spray 2 coats like I described extending out with each coat, then depending on the brand used reduce it or use some blender or intercoat and mix it at least 1(pearl):1(blender), 1:2 would be better. Then spray a final coat again extending out and using the blend technique I described.
Then clear it and you are done. Done correctly it will be undetectable.

If you have any questions ask away. Make sure you practice on something first before trying this.
 
#3
Repaired and shot that exact color many times over the past few years so I'll tell you what works for me.
1. Do your bodywork. Try to contain the repair area as much as possible. Prime (gray is fine) and sand. Finish sand your bodywork (primed area)with 600 wet. If you have any sand through areas re prime and resand.


2 Prep the adjacent panels, meaning the front DS door and the rear quarter. Remove what you can i.e. the mirror, door handle, etc. On the window moldings if you are in any doubt about being able to remove them without damaging them (it's not hard to damage them) leave them on and do what I call a "pull off". I'll explain that later. After you have as much trim etc. removed as necessary then you can start the prep process. I use 800 grit and flatten the orange peel with a soft block (Motorguard roller block) Idea is to level the factory orange peel somewhat. Sand in a back and forth motion, keeping all your scratches going in one direction. Do not cross hatch, and do not sand haphazardly. When you see it start to flatten that is good enough, stop. Do this on the door your repaired including the primed area (just enough to remove the 600 grit scratches) the DS front door and the DS quarter. Don't worry about small areas or edges those will get scuffed i the next step. Now using a grey 3M scotchbrite pad (kind you get at your paint jobber not hardware store type) use some Presta Scuff Stuff or equivalent (available at your Paint Jobber or online look for "sanding paste") wet your panel and the pad and using the scuff stuff start scuffing all three panels. I tend to go either back and forth with the pad or tight circles whichever suits the situation. Make sure you scuff each panel 100%. Pay extra attention to the edges. Rinse and look for any areas you may have missed. You'll notice a slight difference in how a scuffed only area looks versus one you sanded with 800 looks but don't worry about that. As long as it's scuffed that's all you want. Give the entire vehicle a wash or at the very least a good rinse. Let it dry then you are ready to proceed to the next step.

3. Mask the vehicle, do it in such a way as to try and seal off as much as you can. Meaning for example the wheel opening instead of bagging the wheel, back tape around the perimeter of the opening and mask the entire opening off. Doing this will make for a cleaner job. Don't forget your door jambs. I like to leave just a slight amount untaped so there are no unsightly tape lines in the jamb areas. Nothing looks worse than that. Example when taping a door jamb run the tapeup to the seam where the door skin meets the door, leave that folded over area of the skin untaped. When you untape you'll feel and see no transition. As you are taping if you left the window molding on or the window rubber then you'll need to do a "pull off". Simply tape the car up leaving a small gap where the molding meets the paint. Instead of laying down your tape first to the paint you'll do that last. After you have everything taped up, come back to the moulding and tape it. Being very careful to only tape the molding rubber etc. Extend it out past the end and beginning of whatever you are taping and fold a small bit over at the ends to aid you in pulling it off. After your final coat of clear while it is still wet you can pull it off and you'll have no tape line and no risk of lifting in that area like you would if you waited until everything was dry to untape.

4, If you are still with me:) you are now ready to shoot it. After wiping it down tack it off. Undo your tack and let it glide over the surface, don;t use any pressure. Wipe your paper adjacent to paint down as well. Be very thourough. Don't blow it off at this stage as that actually will cause you to get more trash in it. Car should be clean and blown off before you tape.
If you did as I suggest when you prepped it you will not have to seal it. If you have any sand throughs you'll need to seal it though. I'm going to assume you don't and go from there.
First step is your basecoat. It's simply a solid white. Adjust your gun so you are spraying medium coats. Do not spray heavy coats. I cannot emphasize that enough. Light-medium to medium is all you need to do. First coat spray the primed area concentrating on moving in and moving out at the begining and end of each coat. Describing this is hard for me to put into words. Easier to show someone. You want to momentarily pull the trigger and bring your gun in at the beginning and end of each pass. Doing it this way makes it so there are no discernable stop start areas. Some call this wristing off and on. With your gun hand hold it slightly farther out than where you would spray, slightly squeeze the trigger and pull it in then make your pass pulling out the same way and progressively releasing the trigger. Practice this on some masking paper before you try it on the car.
Extend your passes out with each coat until you have coverage.
Next step is the midcoat, in this case a pearlcoat. You will not use Intercoat, it will come with the basecoat from whomever you get your paint from. Depending on the brand you may or may not need to reduce it. More than likely you will, follow the Manufacturers TDS.
You will spray the pearl the same way as the base. Start your first pass roughly where your basecoat begins and finish where it ends. Left to right or right to left whatever works for you. Extend out with each coat. 2 (usually)to 3(max) coats will be all that's needed. If you want to be assured of a nice transition, spray 2 coats like I described extending out with each coat, then depending on the brand used reduce it or use some blender or intercoat and mix it at least 1(pearl):1(blender), 1:2 would be better. Then spray a final coat again extending out and using the blend technique I described.
Then clear it and you are done. Done correctly it will be undetectable.

If you have any questions ask away. Make sure you practice on something first before trying this.
I’m not the original poster but I felt like I needed to thank you for taking the time and effort to write such extensive and detailed reply, not many people would go out of their way to help others, and well not everybody has a way with words to explain things and procedures as thorough as you do.
 
#4
Yes what Chris said and thank you Chris. I would like to add that in Wanda base some of there tri coats can be made into a single base coat and have used them on a few GM colors . I also will do a let down panel on some tri colors.
 
#5
Chris, I cannot thank you enough for your detailed procedure. I really appreciate it. I used the term "inter-coat" which was not what I meant. What I should had used was "mid-coat" which you explained (pearl-coat). Your time and effort will not only help me, but will certainly help others on this forum. I am printing out your procedure and posting it above my work bench (aka - mixing table - LOL).
 
Top