Adding clear activator to base.

5

540goat

Add 1 oz of SPI Clear Coat Activator per mixed quart of basecoat What does this do for the basecoat. I sprayed my GTO with red base about 7 years ago and didn't need it. I also sprayed some medium red on the inside of my corvette doors and didn't add it and haven't had any problems.
 
John Long said:
It will also prevent the solvent from attacking the base if you break through the clear. Without the catalyst in the base it will frequently lift the edge of the break through when attempting to repair. I always catalyze the base.

John
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I always spray clear over a breakthrough and then add base.
 
The base is much more stable and chip resistant when activated. There is a reason the manufacturers require activated base when repairing their cars. Clearing over the breakthrough will work, but is an added step that is not necessary if the base is activated. I remember when DBC came out, and had to repair a spot that got scratched by the bodyman. Feathered out the scratch, went through to the base, sanded rest of panel for clear, spotted the base and it blew up. Never had that problem with DBU because of the activated reducer.
 
Hi Guys, I'm researching older posts to pick up bits of knowledge, and I found this. I have been wondering what actually happens when the base is activated and why its done.

If i understand this right,
1. It allows the base to cross link with the clear for better adhesion (chemical adhesion),
2. It will also prevent a solvent from attacking the base if you break through the clear for what ever reason. I don't understand this completely...Does the "solvent" mean applying more base over the repair area? This will cause it to lift if the original base was not activated?
 
If you ever break through the clear and try to spot/spray base over the area for the repair- the reducer in the base will wrinkle that area. Maybe if you spray REAL light coats and give each coat plenty of dry time you can avoid it - maybe ! The activated base makes the likelihood of it wrinkling much less - still have to be careful though
 
Dave C 5 said:
If you ever break through the clear and try to spot/spray base over the area for the repair- the reducer in the base will wrinkle that area. Maybe if you spray REAL light coats and give each coat plenty of dry time you can avoid it - maybe ! The activated base makes the likelihood of it wrinkling much less - still have to be careful though
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Gotcha, thanks for help in understanding that
 
jsm1947 said:
Whats the mixing ratio? And flash time?
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All bases are different so what we have suggested for years is one ounce of any clear coat activator per mixed quart.
So the weaker bases dont get over-activated due to low OH's.
The few bases that can accept up to 4ozs due to oh the 1%
It makes such a big difference
It's a waste of time and money to add more.
Edit:
Duh, I missed the flash time; it does not make enough to worry about.
 
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Barry said:
All bases are different so what we have suggested for years is one ounce of any clear coat activator per mixed quart.
So the weaker bases dont get over-activated due to low OH's.
The few bases that can accept up to 4ozs due to oh the 1%
It makes such a big difference
It's a waste of time and money to add more.
Edit:
Duh, I missed the flash time; it does not make enough to worry about.
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What about your dark red base? How much can it accept?
 
Dean Jenkins said:
I'm weird I guess. When the chemist dude who formulated the products, and is willing to take calls 7 days a week, and actually uses the product on his own projects, gives guidance, I just follow the guidance.
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Well I would too except he mentioned up to 4oz per quart for *some* good base coat. Since we all know SPI is that good base coat, I thought he might be speaking of this. He clarified his thoughts, however, making a clear recipe of 1oz per quart, even for SPI base. Sounds good to me...


John
 
One cap full for ever mixed qt of base. That's all I have ever use for any base I use. No need to make it any more complicated. I personally don't do it for any other reason than when doing repairs it will stop(or potentially stop) any edge mapping that can occur. Some say it helps metallics lay better, who knows. Some say it helps chip resistance. Again who knows. I dont even know how you would test that to be honest.

But I have had plenty of basecoats wrinkle up on repairs and when I activate the base it doesn't. So I know that part works at least!
 
I have been following the 1 oz per quart of mixed paint for many years now. To be honest, I don't actually measure the activator but guesstimate the amount needed. Especially when mixing small amounts.

The benefits include more chip resistance as well.

When cutting and buffing this Mazda, I broke through the clear on the right fender. It was a small area about 1 1/2" wide and 3" long. This was the first time I took a chance and just shot some more clear over the area. Started with just enough to cover the burn through, then a little larger area and then the entire fender. You couldn't see it no matter how hard or from what angle you looked. I was a firm believer in activating base coat after that.
Front Right View Finished.JPG
 
'68 Coronet R/T said:
I have been following the 1 oz per quart of mixed paint for many years now. To be honest, I don't actually measure the activator but guesstimate the amount needed. Especially when mixing small amounts.

The benefits include more chip resistance as well.

When cutting and buffing this Mazda, I broke through the clear on the right fender. It was a small area about 1 1/2" wide and 3" long. This was the first time I took a chance and just shot some more clear over the area. Started with just enough to cover the burn through, then a little larger area and then the entire fender. You couldn't see it no matter how hard or from what angle you looked. I was a firm believer in activating base coat after that.
View attachment 18907
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'68 Coronet R/T said:
I have been following the 1 oz per quart of mixed paint for many years now. To be honest, I don't actually measure the activator but guesstimate the amount needed. Especially when mixing small amounts.

The benefits include more chip resistance as well.

When cutting and buffing this Mazda, I broke through the clear on the right fender. It was a small area about 1 1/2" wide and 3" long. This was the first time I took a chance and just shot some more clear over the area. Started with just enough to cover the burn through, then a little larger area and then the entire fender. You couldn't see it no matter how hard or from what angle you looked. I was a firm believer in activating base coat after that.
View attachment 18907
Click to expand...
Wow!
 
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