Base coats and flash times

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PostPosted: Fri Nov 29, 2019 10:45 pm
So I am sort of continuing on from a previous topic.

Having never used base coats in painting and I have been painting daily (not cars) for at least 30 years, i have some flash time questions.

With a candy red example.

Sealed/primed ready to go. I mix up two spray guns, one with mettalic gold, one with mettalic red.

Question 1 - First coat of base over a 600 sanded surface should i make that 1000 sanded

Question 2 - Flash time ? 5 minutes between coats or should i wait longer, i actually use a kitchen timer to remind me as i have moved back to another job.

Question 3 - if i have to do some pin striping and lay down tape what waiting period and prep process should I be doing.

Question 4 - clear coats, am I still sticking to 5 minutes between coats or should I blow that out to 15, is first coat of clear after 5 minutes or should i have a longer gassing out period.

Sorry for all the questions, after my first go getting the previous results, want to make sure I have my flash times right

Steve

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PostPosted: Sat Nov 30, 2019 4:22 am
Q1: In my experience some metallics/pearls will show the scratching from P600. I use P800 for metallics and P600 for solids.

Q2: Flash times can vary by basecoat. For example if I use the Centari 6000 premium base then flash times can be very short because the thinners content is relatively low at 1:4. If I use the budget 610 base, where the reducer ratio is 4:5 to the base then flash times need to be a bit longer. This can vary more if I use fast, medium or slow reducer to account for weather or effect. The general rule is that the base should appear flat, not wet before spraying another coat. The TDS should give you a guide but you need to verify with some experience. I don't have the luxury of being able to hold up the booth since there's usually another job waiting so I push flash times but still use a kitchen timer, as you do.

Q3: If taping I always give the base more time and if it's masking then I only use low tack tapes. Half an hour in warm weather, an hour if cooler although I might put the heat lamps on just to be sure. Again varies with paint used.

Q4: Clears vary wildly and can also depend on how you laid the previous coat. I'm using a new clear that allows a second coat almost immediately after finishing the first and if I wait too long the clear goes off around the needle and fluid tip. But, if doing a big horizontal job like a bonnet or roof I'll use a much slower clear where flash times need to be 10-15 minutes. Best way with clear is to check for tackiness before recoating.
Chris



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PostPosted: Sat Nov 30, 2019 7:16 am
Thanks.

Great starting points for me, I will check and time how long things go re visual appearance, will also swap out to 800 for mettalics.

On your pin striping 30minutes ish, if i have taped and masked off, is 30 minute window still okay for the next base coat or should i gold pad scuff to key the next coat

Steve

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PostPosted: Sat Nov 30, 2019 11:26 am
simso wrote:Thanks.

Great starting points for me, I will check and time how long things go re visual appearance, will also swap out to 800 for mettalics.

On your pin striping 30minutes ish, if i have taped and masked off, is 30 minute window still okay for the next base coat or should i gold pad scuff to key the next coat

Steve


What materials are you using?

Definitely go to 800, I also like to use scuffing paste as part of my final prep.

You should be fine after 30 minutes or more, many times I wait until the next morning to add more BC or clear.
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PostPosted: Sat Nov 30, 2019 8:01 pm
Thanks, the products are Valspar beyond that I have no idea :).

I do not know what scuffing paste is

Steve

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