Clear over activated base?

M

MKH

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Hi, i have just sprayed 5 coats of diamont activated base. 30 minutes between coats. How soon can I spray SPI universal clear? I had planned to wait over night but the forecast has changed to rain for tomorrow. That may not be an issue as I paint in my garage and have a filter set up for the garage door. Thanks
Mike
 
5 coats of Diamont is a lot, and on something like you are working on Mike you would want to wait overnight. At least 12 hours and keep the temps up in the painting area as well. Humidity would probably not be a factor if you are using some heat in the painting area. You could also wait a day or so till the rain moves out and humidity lessens. You would not have any issues waiting 24 hours or longer. You can recoat activated base with clear for quite some time irregardless of what the TDS of the base may say. Me, I would probably turn the heat up a touch and run a dehumidifier and do it after 12+ hours. That should keep the humidity down while you are spraying.
 
Chris, thanks for the reply. I misspoke a little I had to spray 3 coats over some primer work to get it covered and then 2 more coats over the entire front cap. So 5 coats over the primer area and 2 coats over the rest.
Mike
 
5 coats is a lot, I almost never use that many except perhaps on a 3-stage pearl. Did it really cover so poorly? Wait as long as you can! It's going to shrink in some no matter what.
 
crashtech said:
5 coats is a lot, I almost never use that many except perhaps on a 3-stage pearl. Did it really cover so poorly? Wait as long as you can! It's going to shrink in some no matter what.
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It’s a light pale yellow or ivory. It took 3 coats to cover the SPI 2k primer. Once it covered the primer I shot 2 coats over the entire front cap. I was just going to do a blend but since I had the whole front cap sanded with 800 I just shot the whole front cap. I should have stopped at the blend as the front cap dosent match now. I guess I get to paint the rest of the car!!!!
 
Oops! Well, we've all been there. But I think it's best to limit the number of coats of base to the minimum required to cover, since it's the weakest link in the system. Just something to think about for the next time.
 
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I just do this for myself. But I can tell you it’s a very unforgiving hobby!! At least the mistakes I do make are very time consuming and expensive so I don’t make them twice!!!
Mike.
 
crashtech said:
Oops! Well, we've all been there. But I think it's best to limit the number of coats of base to the minimum required to cover, since it's the weakest link in the system. Just something to think about for the next time.
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@crashtech.......why is base the weakest link?
 
I'm not Crash but I can give the answer. It's the weak link because in a modern paint system it's the only product that doesn't dry/cure by activation/catylzation. Even activating base doesn't really activate it...ie a chemical reaction. It just dries along with the base allowing the base to be a little harder and less susceptible to solvent.
When a product cures by chemical reaction as opposed to drying by evaporating solvent it's tougher and more resistant to solvent from subsequent topcoats.
 
Do yall think my issue with the color was because I activated the base? I had the hood scanned and purchased 8 oz diamont. I sprayed the hood with the sample and did NOT activate it. I set it on the car and it was a perfect match. I then ordered a pint of paint from the same supplier. Mixed 2-1 and activated it, sprayed the front cap and now it dosent match. I guess my question is can the activator change the base color?
 
MKH said:
Do yall think my issue with the color was because I activated the base? I had the hood scanned and purchased 8 oz diamont. I sprayed the hood with the sample and did NOT activate it. I set it on the car and it was a perfect match. I then ordered a pint of paint from the same supplier. Mixed 2-1 and activated it, sprayed the front cap and now it dosent match. I guess my question is can the activator change the base color?
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No activation would not really change the color. More than likely you got someone who didn't mix the formula to the exact amounts. Happens more often than you think. You mix a formula on a scale adding toners by the amount of grams. If he went over or under on one of the toners, throwing it out would be expensive so instead just finish adding toners to the formula and it's off by a slight amount.
 
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Chris_Hamilton said:
I'm not Crash but I can give the answer. It's the weak link because in a modern paint system it's the only product that doesn't dry/cure by activation/catylzation. Even activating base doesn't really activate it...ie a chemical reaction. It just dries along with the base allowing the base to be a little harder and less susceptible to solvent.
When a product cures by chemical reaction as opposed to drying by evaporating solvent it's tougher and more resistant to solvent from subsequent topcoats.
Click to expand...

Now I know, thank you.
 
I'm not a pro but have made plenty of mistakes and discoveries along the way. One more thing to consider with lighter colors, is that they can require a specific undercoat/sealer color to achieve the desired finished color.
 
Chris_Hamilton said:
No activation would not really change the color. More than likely you got someone who didn't mix the formula to the exact amounts. Happens more often than you think. You mix a formula on a scale adding toners by the amount of grams. If he went over or under on one of the toners, throwing it out would be expensive so instead just finish adding toners to the formula and it's off by a slight amount.
Click to expand...
I got a local guy that can’t mix the same color code twice the same day to save his life. Thinking he’s in the wrong business lol.
 
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