Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (http://www.hotrodders.com/forum/)
-   Body - Exterior (http://www.hotrodders.com/forum/body-exterior/)
-   -   SEM Hotrod black "grit in it when sprayed" (http://www.hotrodders.com/forum/sem-hotrod-black-grit-when-sprayed-196842.html)

cyclopsblown34 04-20-2011 08:18 PM

SEM Hotrod black "grit in it when sprayed"
 
The HOK satin black my paint guy sold my buddy exhibits the signs of old reducer, it is in fact SEM hotrod black in kit form a quart of black, 8 ounces of reducer and eight ounces of catalyst. The first coat I sprayed had the grittiness you get when using old reducer. The second coat, I used Nason medium urethane reducer, same story. Third try, SEM paint, Nason medium reducer and Nason ful thane hardener, same story. I know the Nason is good because it is what I used this weekend with the flattening compound fiasco that resulted in a flawless finish but too shiny, it did dull/flatten eventually but I don't think I can repeat those results as far as sheen. This has all been done on similarly prepared square gallon cans from reducer and SPI clear. Is it Iso clumping causing the problem with the SEM? Each application was on a different can. I did mix up Nason black and throw in some flattening compound just for grins and it sprayed out smooth and we'll see if it flattens.

Man,that's one long old paragraph.
Sorry about the rambling paragraph,
Chip.

milo 04-20-2011 11:48 PM

The Sem should be thinned with a lacquer thinner not reducer unless your in California and then they say a"SR" reducer to be VOC compliant.

mabe try some good lacquer thiner and thin it about as thin as water(17 seconds#2 Zahn cup) and see how a test panel turns out..

BarryK 04-21-2011 05:06 AM

If you used a urethane reducer in this (right or wrong) that did not cause the grit.

I THINK this stuff is an enamel base, IF I'm right then you have a seedy activator (bad)

Urethane activators will not cause a seed as they just get weak and don't dry right, enamel activators will seed. (kinda a good warning system)

cyclopsblown34 04-21-2011 05:08 AM

Thanks Milo, this is the SEM HR010 kit, it was sold to my buddy as House of Kolor, I was kinda let down and my opinion was tainted when I saw the brand name. This thing has Spies base and SPI clear, to me SEM is on par with Nason or Kirker. I'm going to check with SEM today since all three items are labeled with lot numbers. We may end up just trying to either mix the Nason single stage black with flattening agent or see if somebody can find me a code for GM underhood black and get that mixed in single stage urethane.

BarryK 04-21-2011 05:26 AM

One other thing that can cause this but rare, is if the product froze in the past and now you have a pigment kick out.
The pigment will not strain out through normal strainers and you can not mix them back in without heating to 175 degrees and using a high speed disperser.

Rare but does happen.

BarryK 04-21-2011 05:29 AM

GM underhood black and get that mixed in single stage urethane.


Black epoxy??????

jcclark 04-21-2011 05:33 AM

Barry, does that paint have a flattener in it?
Can that be the culprit? :cool:

BarryK 04-21-2011 05:35 AM

Unlikely as the flattener if out of suspension or to high air pressure will show white snow flakes.

cyclopsblown34 04-21-2011 06:37 AM

Barry, your epoxy is what I suggested and when I sprayed it, he thought it too flat. He's trying to replicate the black he has underhood and it is a satin black. I'm thinking about suggesting underhood black and be done with it. It'll definitely be a SS urethane and not enamel.

milo 04-21-2011 07:04 AM

I used the SEM Trim Black from a aresol can on the Duster hood in this thread..
http://www.hotrodders.com/forum/sem-...sem+trim+black

The mix in the spray cans is laucqer as well as in the quart cans but mabe thats the difference between the "Hot Rod Black" and "Satin Trim Black" formulas ..

*use a good respirator with either of these,,. theres something extra bad in there in this reporters opinion

jeremyb 04-21-2011 07:13 AM

1 Attachment(s)
are you just dead set on using a ss with flattener? there are good mat clears out there....sikkens/lesonal has one and ppg has one...i'm sure the other guys do.


attatched pic is just one nice wet coat of the sikkens mat clear......2 coats with proper flash will give a little more gloss than in the pic.

cyclopsblown34 04-21-2011 07:13 AM

Thanks Milo, I wear a respirator, even when cleaning my guns or mixing paint. we may end up using an aerosol SEM trim black.

cyclopsblown34 04-21-2011 07:15 AM

Quote:

Originally Posted by jeremyb
are you just dead set on using a ss with flattener? there are good mat clears out there....sikkens/lesonal has one and ppg has one...i'm sure the other guys do.


attatched pic is just one nice wet coat of the sikkens mat clear......2 coats with proper flash will give a little more gloss than in the pic.

Jeremy, I wasn't even giving that a thought, thanks for the idea. I'll contact my paint guy and see if DuPont offers a matte clear. If not, I'll contact my PPG guy.

jeremyb 04-21-2011 07:57 AM

with the sikkens you can also cocktail it with any of their clears to give more gloss......which works better, i think, than any pure flattening agent...atleast with this system.

you arent going to get a purely FLAT finish with this system.

deadbodyman 04-23-2011 12:29 AM

Why not get the paint code for a challenger....they can look it up at the paint store ,this way you can use ANY brand you want...


All times are GMT -6. The time now is 12:21 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.