[savage57]

Can someone tell me the difference between Kp21 and kp2cf and if you would recommend one over the other? I will be using a shimrin metallic bc but the tech sheets seem to say the same thing for both except for one states that it is a voc 2.1 high solids. I am new to this and would like some direction before purchasing materials or relying on the local paint shop. There seems to be alot of experience here and I would appreciate your opinions.

[mrcleanr6]

i use alot of hok products on a daily basis however i've never used their epoxy. i looked in the tech manual and seems to me the only difference is that one lacks the zinc chromate and isn't low voc where the other one meets the low voc scaqmd. i guess it really depends on where you live and the laws. thats the only difference i see.

[Bee4Me]

kp-21 is the one to use.
The cf is a lesser version and if I recall,will go DORMANT under 70*.
You can actually store it in the frige for use later if you want.

[Randy Ferguson]

I tried both when they took the old EP-2 off the market. The KP-21 is formulated to strict VOC compliency, and last I knew of, they put this stuff out to meet the VOC requirements for California. I didn't like it, as it was hard as a rock to sand. I liked the KP2CF better from a sanding standpoint, but had problems with adhesion both times I used it. I dumped the HOK epoxies for SPI, which I now believe to be the very best epoxy on the market. I've tried many, not all, but this stuff from SPI is just awesome!!! It sprays great, sticks like glue and sands very nice!

Randy Ferguson
Ferguson Coachbuilding

[old40ford]

Originally Posted by Randy Ferguson

I dumped the HOK epoxies for SPI, which I now believe to be the very best epoxy on the market. I've tried many, not all, but this stuff from SPI is just awesome!!! It sprays great, sticks like glue and sands very nice!

Randy Ferguson
Ferguson Coachbuilding

couldn't have put it better.

[beemdubya]

If u read some of my older posts i had a HUGE problem with the hok epoxy. it was so bad i ended up stripping it off an entire car... and it adhered so poorly that 95% of each panel i used a razorblade to scrape it off and it came off in huge sheets.. i tried it with a metal etch.. without a metal etch... just didnt work..

I now only use the SPI epoxy.. im not gonna say that is the only stuff that works but there is nothing good about the hok epoxt.. and i even here ppg's new epoxy isnt all that either.

[keith1]

I used their epoxy and had it come off in sheets when I was blowing it off with a blow gun. I stripped it all off and switched to SPI.

[mrcleanr6]

well i guess i'm lucky to have never tried it. i've used spi from the beginning.

[62galaxiguy]

I used to use there kp21 all time on kustoms great adhesion and would block it with 120 dry.i used it for about 4 years but the COST MY GOD>215.00 for 2 gallons sprayable 1:1 reduction,But have switched to SPI epoxy there cost is much more in line and barrys great if you need info on the product.mike

[Mag]

I am far from an expert, but my understanding is that the cf is manufactured to comply with Cal. voc standards. The kp21 is what hok recommends for most applications. I've only done two paint jobs, and used kp21 on both. I had no adhesion problems at all over bare steel or fresh fiberglass gelcoat. It was a little hard to sand, but both times were on motorcycle parts, so I didn't mind. My thinking at the time was that it was supposed to be a little harder to sand, providing a more durable foundation for the color coats that followed. I'll use it again on the next one.

kevin