47-55.1 Guidance preping for paint with new Mar-k bed

[rnrdthefox]

I purchased a new bed from Mar-k. It appears to be excellent quality and very straight visually. My question is about paint prep. Is it feasible to shoot it with Epoxy then go straight to high build polyester? Are these beds good enough to do this? I can do a skim coat of filler if needed, just trying to save some time. Thanks.

[gsinon]

I can't speak about all paint companies, but for PPG you can't put poly primer over epoxy unless it has cured for a long time. I've seen people do it, then after paint the paint will "gas out" and it will look like the car has the measles.

PPG has a high build epoxy, VP2050, or CRE that you can go direct to metal and have epoxy qualities but it has the build of polyester.

[rnrdthefox]

Originally Posted by gsinon

I can't speak about all paint companies, but for PPG you can't put poly primer over epoxy unless it has cured for a long time. I've seen people do it, then after paint the paint will "gas out" and it will look like the car has the measles.

PPG has a high build epoxy, VP2050, or CRE that you can go direct to metal and have epoxy qualities but it has the build of polyester.

Thanks for the reply. I wasn't very clear on my question. I wondering what others have experienced with these beds as far as how straight they are and if i could skip a skim coat of body filler and go straight to polyester and block sand from there.

[gsinon]

Oh ok. Maybe I just misread the question.

Here’s how I look at that. For the most part the outsides are pretty good and the majority of the sides are covered by the fenders. I suspect that if anything you may want to do the inside of the sides.

To tell, wet the bed sides with a wax and grease remover and sight the length of them and see how straight they are.

[mongocanfly]

I have a all mar-k bed here..based on what I see itll need epoxy, which means the surface needs roughed up..I'm gonna hit mine with 80g then spray epoxy..the epoxy will give me a good thickness to smooth while sanding ..but from what I've seen , the panels are in great shape..but as you know, packing ,handling , and shipping , might not have been a gentle ride..so there could be things that need fixed..
But . I'll epoxy, smooth it, fix what needs fixing, then epoxy again, smooth it, then high build , smooth again , followed by paint

[rnrdthefox]

Originally Posted by mongocanfly

I have a all mar-k bed here..based on what I see itll need epoxy, which means the surface needs roughed up..I'm gonna hit mine with 80g then spray epoxy..the epoxy will give me a good thickness to smooth while sanding ..but from what I've seen , the panels are in great shape..but as you know, packing ,handling , and shipping , might not have been a gentle ride..so there could be things that need fixed..
But . I'll epoxy, smooth it, fix what needs fixing, then epoxy again, smooth it, then high build , smooth again , followed by paint

Ok. That's kind of what I was thinking. Just wanted to get a few opinions. Thx

[duramax55]

rn rdthefox i wouldn't go less than 240 to scuff it down then go high build block with 240 to noke it down and move to 320 and 400 for singel stage paint. at any point if you see its not going to get all the low spot re shoot win high build.forgot to mention to use guide coats between grit change. guide coat help to see low spot's. go to 600 for a base coat clear coat. just how i do it. when doing high build do at least 2 coats and wait for it to flash between coats about 20 minutes better to wait a bit more than to try and rush to put it on

[dsraven]

yep, if it doesn't cure enough between coats then the first coats will offgas and create bubbles in the top coat....trust me. you can peel it off like saran wrap

[mr48chev]

Back in the early 80's some guys were saying that the spot welds showed up big time on Mar-K bed sides . That is the only gripe I have ever seen on them.

It's like anything you buy for these trucks, you may have to do a bit of work to get to the level of perfection you want.

[mongocanfly]

the mar-k panels are electro-galvanized...make sure whatever you do its compatible

[rnrdthefox]

Originally Posted by mongocanfly

the mar-k panels are electro-galvanized...make sure whatever you do its compatible

Good point. That was another question that I had about what type of coating it had. I'll check the tech sheet to make sure this is good with the epoxy.

[mr48chev]

There is more info on this PFD that you are going to want when you assemble the bed but scroll down a ways and they cover painting the electro galvanized parts. https://www.mar-k.com/PDFs/Instructi...Wood-Floor.pdf

You probably want to save that PFD to the computer as I am pretty sure you will be going back to it a few times. Found with a Google search rather than hunting the website.

The concept is sand the Zink but don't go through the Zink.

[rnrdthefox]

Originally Posted by mr48chev

There is more info on this PFD that you are going to want when you assemble the bed but scroll down a ways and they cover painting the electro galvanized parts. https://www.mar-k.com/PDFs/Instructi...Wood-Floor.pdf

You probably want to save that PFD to the computer as I am pretty sure you will be going back to it a few times. Found with a Google search rather than hunting the website.

The concept is sand the Zink but don't go through the Zink.

Thanks for this. I don't remember this document when I got the bed. I also didn't know that they had a hidden fastner option to the bed strips. I would have likely ordered those before I bought the polished stainless set from LMC. Live and learn. Thanks for all the other comments as well. Much appreciated. Thanks.

[_Ogre]

I wouldn't use 80g anything on any body panel with e-coat or primer on it
Start with reading the PDF mr48 posted
I'd likely scuff it with W&G remover and a scotchbrite

[mongocanfly]

I'll be using spi primers on my stuff..so I'll go with what they say..
When I said 80g and epoxy , I was thinking more of my fenders, which arnt coated ..
The mar-k stuff may not need epoxy..but if epoxy is to be used, it needs something aggressive to bite into

[MARTINSR]

I am THRILLED with the quality of the Mar-k bed. Mine got an SPI epoxy primer, done deal.

Brian

[BIGglaSS]

It depends if you are going for a driver quality or show. For driver quality, you could get by with just epoxy. My Mar-K bed still needed filler on the opposite sides of the spot welds, and tops of the rails. The vertical stake pockets took A LOT of filler!

They were not flat enough for just epoxy. I started with 80 grit on the D/A. Shot with epoxy, then filler work. Then Featherfill G2. Sealed with epoxy, then base/clear.

Polyester primer over epoxy would depend on the product you're using. I use SPI epoxy, and it is OK to put poly primer over IF you wait at least 48 hours.

[rnrdthefox]

Originally Posted by BIGglaSS

It depends if you are going for a driver quality or show. For driver quality, you could get by with just epoxy. My Mar-K bed still needed filler on the opposite sides of the spot welds, and tops of the rails. The vertical stake pockets took A LOT of filler!

They were not flat enough for just epoxy. I started with 80 grit on the D/A. Shot with epoxy, then filler work. Then Featherfill G2. Sealed with epoxy, then base/clear.

Polyester primer over epoxy would depend on the product you're using. I use SPI epoxy, and it is OK to put poly primer over IF you wait at least 48 hours.

Yes, I agree after spending the long weekend prepping the metal for epoxy, I noticed a few places with the spot welds that will need some work. I noticed a few large dimples in the stake pockets from the bending process that will need some work with filler.

Thanks for all the comments.