Body Undercoat

[Cleve]

Any recommendations for a good roll on undercoat.
Thanks
Cleve

[FLPBFoot]

I used Herculiner from Menards. Works great but has some nasty VOCs. Wear a good respirator and open all the garage doors.

[CaptB]

I used this:

https://tcpglobal.com/products/cus-sp-446-3pk?currency=USD&stkn=ea543c203691&gad_source=1&gclid=Cj0KCQjw8MG1BhCoARIsAHxSiQnCDrW3r5Kp5PcW61tJ SFdtMOWyi2CW9ce1f0wJbxM9nZMsQn4Zoc0aAopuEALw_wcB

It isn't required but it is a good professional looking touch. Did this right before body work.

[Jeff Kleiner]

For years I did them with Herculiner, Duplicolor Bed Armor or some of the various rubberized coatings but a few years ago I tried U-Pol Raptor and will never go back. It's great stuff! I buy the gallon kit and spray it on using a Schutz gun however it can be applied by brush/roller. It's available in 2K Aerosols but that's more intended for small areas or touch up repairs and wouldn't be cost effective to use that for an entire body. By the way, it takes the full gallon kit to do a roadster body. I apply it after paint, cut & buff right before putting the body back on.

https://u-pol.com/en-us/brands/raptor/

Jeff

[juddster]

Ditto on the U-Pol Raptor. I was going to spray but ended up doing the roll on. Went great. I did mine before paint so I made sure tape off edges about an inch or so in. I followed the recommendations of my painter.

The undercoat dissolves the rollers quickly. Make sure to have extra on hand. I mixed mine a liter at a time and ended up using 3-4 rollers and wished I had more.

So glad I did the undercoat as you can see the underside of the body in places. Nice to have a black surface rather than the red underbody.

[emac]

Body shop used 3M body shutz on my roadster back in 2012 and it still looks great. He said it wold help with rocks from underneath coming through and damaging paint. Recently, I restored a 240z and used the Raptor product underneath, and painted body color over it for a factory look. It was great and has a nice finish that came close to the factory. Super tough.....so dont get it in any threaded holes!

[Rebostar]

Ditto on the Raptor, Great stuff, nothing better out there. I sprayed it on using the kit supplied gun, but as J.K. mentioned it can be rolled on. Best of all you can get it in clear/tintable, so you dont have to settle for black.
202590

[Kbl7td]

For those of you with paint and raptor experience. Where are you putting your tape line? The body has thickness to it, does that thick portion of the body get paint or undercoat?

[gbranham]

I was just reading about U-Pol Raptor on their website. My math is failing me...it says "with a 3:1 mix ratio, use one quart of hardener to a gallon of Raptor". How is that 3:1? Isn't that 4:1?

[Tooth]

I used the raptor. Got a kit with spray gun and everything on amazon.

[Jeff Kleiner]

I was just reading about U-Pol Raptor on their website. My math is failing me...it says "with a 3:1 mix ratio, use one quart of hardener to a gallon of Raptor". How is that 3:1? Isn't that 4:1?

The gallon kit produces 1 gallon MIXED. It includes 96 ounces of product in (4) 24 ounce containers and one 32 ounce container of hardener/catalyst. Each 24 ounce jug gets 8 ounces of hardener.

Jeff

[gbranham]

The gallon kit produces 1 gallon MIXED. It includes 96 ounces of product in (4) 24 ounce containers and one 32 ounce container of hardener/catalyst. Each 24 ounce jug gets 8 ounces of hardener.

Jeff

Ah, gotcha. That makes sense. I'll just pay you to apply it when you paint my car. :)

[Buzzsaw]

Guys,
Is there any prep work that needs to be done before spraying or rolling? Any overspray issues when spraying? Is one coat sufficient? Looks like the Raptor is really good stuff. Just about ready to under coat my body.

[Rebostar]

I sprayed the Raptor (tinted grey with urathane primer) on all the outside & bottom facing sides of the aluminum panels. I used red scotch brite to give some tooth to the aluminum before shooting the Raptor liner, though I dont think it was nessasary. The stuff sticks to anything and is tough as nails. Then I cleaned with acetone. On the body underside, I'll be scuffing with 80 grit to remove any loose fibers, then shoot it with grey tinted Raptor.