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Paint base color butting - Pro -Question

BillL

Well Known Member
I wanted by color changes to be smooth, no ridge, and mostly got that. Now I want to replace some parts and matching the paint is on the table.

I have black, white and metallic blue in SkyScape standard colors - base/clear.

Does anyone have some successful experience in doing this so the colors butt and are not just layered on so the masking is easy? You know, all black, mask, all blue, then all white so we have 1-2-3 layers of paint in areas and the thickness in the step??

Here is a very old video and look how he masks with a tiny overlap, then scrapes off the ridge before doing the top coats. Look at 43:10>43:46 for masking and 52:10>53:08 for the scraping. Cool tricks in this vid if you have the time.

Will this work on urethane paints like SkyScape??
 
I typically lay down one color of base coat, let it dry for an hour or two then put down 3M fine line tape to mark the line. Then add masking and then spray the next base color. Yes this will leave an edge once the tape is removed, but the base coat is so much thinner than the clear coat that you will barely notice it at three coats. If you only use two coats or thin coats, you may have a slight line in the clear but is easily removed with wet sanding with a moderately firm block. This method does leave an edge, but is not a ridge, only a cliff shaped abutment that is easily sanded out of the clear with 1000 grit. Follow with 1500 before buffing.

While I have never done a job requiring it, many use multiple layers of masking with different colors successfully. However, you must be cautious not to let the tape layers build up at a paint edge. If you have two layers of tape at a cut line, the base coat will build to twice the height at the transition. The higher that cliff is, the more it will be noticeable after clear and there will be more clear to remove to get rid of it.

Always use fine line tape. It is quite thin and leaves a nice clean edge. The thicker tape will cause the base to be thicker at the transition and will leave a more pronounced line in the clear. Always pull the tape off up or down and towards the remaining tape at a sharp angle, so that it cuts and not tears the base off the primer. Base does not have strong adhsion.

Trying to butt colors seems like a dangerous game. Any error at all will stand out like a sore thumb. Then you are doing difficult touch up with a very fine brush. In my experience, that is almost impossible to do without too much build up from the brush (surface tension causes a dome shaped, vertical profile). The more common alternative used in fancy paint schemes, other than airbrushing, it to use inter-coat clear between base layers. This flattens things out and provides the time necessary for very detailed base work.

Larry
 
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This is how John Stahr painted my little jet - it is not overall one color with other colors on top. It is all primed, then he laid out the pattern for the “pinstripes” - all colors are separated by thin gold lines - and painted those. Then he taped to those lines for each color individually and painted those (covering the other areas with sheet masking). Then he did the air brush work, and finally clear-coated the whole thing - voila’…no raised edges where the colors meet.

It was amazing to watch and help - and the whole process was done in six has - and on the seventh, he rested! ;)
 
Here is how I would do it.

Mask for your first color and paint
When dry remove all tape
Mask for second color and paint
When dry remove all tape
Mask for final color and paint
Remove your tape
Mask the panels you painted on
Lightly sand the color lines with 800 grit.
Re-clear the panels

If after you clear you still think that there is an edge that you can feel that is not to your liking, block sand the panel with 800 grit and clear again. There will absolutely be no edges at that point.
 
Seams

Here is how I would do it.

Mask for your first color and paint
When dry remove all tape
Mask for second color and paint
When dry remove all tape
Mask for final color and paint
Remove your tape
Mask the panels you painted on
Lightly sand the color lines with 800 grit.
Re-clear the panels

If after you clear you still think that there is an edge that you can feel that is not to your liking, block sand the panel with 800 grit and clear again. There will absolutely be no edges at that point.

Bingo! I was waiting for someone to post that. That's how it's done. Block sand the whole base coat including seams then spray the clear.
 
Video

...
Here is a very old video and look how he masks with a tiny overlap, then scrapes off the ridge before doing the top coats. Look at 43:10>43:46 for masking and 52:10>53:08 for the scraping. Cool tricks in this vid if you have the time.

Will this work on urethane paints like SkyScape??

Interesting cool video! I watched the whole thing and noticed a few tricks. He paints the whole side in one sweep, walking the gun over the entire length. That should work to reduce the likelihood of runs on wings and fuselage? Also he holds the gun quite close to the surface and the fan seems narrower than normal. It doesn't seem to bother him about spilling paint while mixing! The job was a lot of work but the end result looked great including the stepless transition between base coats.
 
. . . However, you must be cautious not to let the tape layers build up at a paint edge. If you have two layers of tape at a cut line, the base coat will build to twice the height at the transition. The higher that cliff is, the more it will be noticeable after clear and there will be more clear to remove to get rid of it.

Always use fine line tape. It is quite thin and leaves a nice clean edge. . . . The more common alternative used in fancy paint schemes, other than airbrushing, it to use inter-coat clear between base layers. This flattens things out and provides the time necessary for very detailed base work.
Larry

Thanks Larry, the surface tension of the paint is a variable can work against a good job - -I have seen the trick of a light (essentially a seal) clear coat to allow sanding for extending the recoat time and allowing denibbing the base.

This is how John Stahr painted my little jet - it is not overall one color with other colors on top. It is all primed, then he laid out the pattern for the “pinstripes” - all colors are separated by thin gold lines - and painted those. Then he taped to those lines for each color individually and painted those (covering the other areas with sheet masking). Then he did the air brush work, and finally clear-coated the whole thing - voila’…no raised edges where the colors meet.

It was amazing to watch and help - and the whole process was done in six has - and on the seventh, he rested! ;)

This sounds like exactly what I am looking for! If I understand correctly the gold stripe is between two other colors and butted to each, all covered by a clear topcoat?

Here is how I would do it.

Mask for your first color and paint
When dry remove all tape
Mask for second color and paint
When dry remove all tape
Mask for final color and paint
Remove your tape
Mask the panels you painted on
Lightly sand the color lines with 800 grit.
Re-clear the panels

If after you clear you still think that there is an edge that you can feel that is not to your liking, block sand the panel with 800 grit and clear again. There will absolutely be no edges at that point.

Brandon, thanks for responding - - So, the masking is using some thin sharp fine line vinyl with a setback to the masking tape holding the paper/film mask? I am a little lost after the last "remove your tape" step - could you expand a little? And when you say "sand the color lines" is that butted base coats or is any clear on there at all?

I have read that sanding metallic base coats is "bad", can you help with that?


All - -good responses to the point, THANKS!!
I am going to have to spend some training $$ and buy some guns, paint and practice.
 
My PC is M.I.A. at the moment so I can’t do a ms paint picture to help describe this but here it goes anyway.

When you paint you add a layer of a certain thickness to the surface. This layer flows over the tape edge also. When you peel off your tape, the edge has a little uptick where it went over the tape. The idea here is to sand down that high spot. This makes it a lot easier for the clear to smooth it up. The trick is to not sand so much that you break the crisp-ness of your color edge.

I hope I’m describing this ok. If not, let me know. I’ll try to do better.

Thanks Larry, the surface tension of the paint is a variable can work against a good job - -I have seen the trick of a light (essentially a seal) clear coat to allow sanding for extending the recoat time and allowing denibbing the base.



This sounds like exactly what I am looking for! If I understand correctly the gold stripe is between two other colors and butted to each, all covered by a clear topcoat?



Brandon, thanks for responding - - So, the masking is using some thin sharp fine line vinyl with a setback to the masking tape holding the paper/film mask? I am a little lost after the last "remove your tape" step - could you expand a little? And when you say "sand the color lines" is that butted base coats or is any clear on there at all?

I have read that sanding metallic base coats is "bad", can you help with that?


All - -good responses to the point, THANKS!!
I am going to have to spend some training $$ and buy some guns, paint and practice.
 
Bingo! I was waiting for someone to post that. That's how it's done. Block sand the whole base coat including seams then spray the clear.

Base coat cannot be sanded before clear unless another coat of base goes after the sanding. At least with most Poly paint systems. Cetain elments float to the top for adhesion and protection from the clear. Knocking that off by sanding is not recommended with most companies base coats. Read the TDS. Clearly says that any sanding of the base coat must be followed by applying another coat of base before clearing.

scraping off the ridge is different than sanding the base coat. I suspect that requires an artistic touch to avoid ruining the base coat. I have scraped of several clear coat runs with a razor blade, but the base is WAY softer and thinner than clear. Still think it is easier to scrape off the ridge or wet sand after the clear for us mere mortals that don't paint for a living.

Larry
 
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Not an issue with Sherwin Williams Skyscapes or AkzoNobel 4400. They are not like automotive base/clear systems.

Base coat cannot be sanded before clear unless another coat of base goes after the sanding. At least with most Poly paint systems. Cetain elments float to the top for adhesion and protection from the clear. Knocking that off by sanding is not recommended with most companies base coats. Read the TDS. Clearly says that any sanding of the base coat must be followed by applying another coat of base before clearing.

scraping off the ridge is different than sanding the base coat. I suspect that requires an artistic touch to avoid ruining the base coat. I have scraped of several clear coat runs with a razor blade, but the base is WAY softer and thinner than clear. Still think it is easier to scrape off the ridge or wet sand after the clear for us mere mortals that don't paint for a living.

Larry
 
My PC is M.I.A. at the moment so I can’t do a ms paint picture to help describe this but here it goes anyway.

When you paint you add a layer of a certain thickness to the surface. This layer flows over the tape edge also. When you peel off your tape, the edge has a little uptick where it went over the tape. The idea here is to sand down that high spot. This makes it a lot easier for the clear to smooth it up. The trick is to not sand so much that you break the crisp-ness of your color edge.

I hope I’m describing this ok. If not, let me know. I’ll try to do better.

Thanks, but I am slow with the detail here. Below is a crude sketch of a coat with mask, what gets removed and how it should look when ready for the next mask and color. So should the next mask leave a tiny "reveal" so it can be sanded down to level and leave a sharp butted edge between colors?

Is this along the correct thinking or way off? Thanks for hanging in here on this topic.

View attachment Paint masking.pdf
 
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