Frame Painting Steps

[BoureeOne]

I am about to have my frame taken to the sand blaster. I want to have all my ducks in a row to paint the frame. As I have read in several post, it looks like one of the most common choices is POR 15. Here are my questions. Are you guys applying this directly to the bare metal, or are you using a primer first? If primer, which one and how are you applying it, with sprayer or brush? How are you applying the POR, sprayer or brush? Are you coating the inside of the frame? If yes, how? Also, are you putting any type of coating on top of the POR 15? Have seen ads for a separate Gloss coat on top of the POR 15.

Thanks in advance.

Scott

 

[nickgp]

Why use POR if you are sandblasting? Paint over rust? Since the rust will be gone I assume, why not epoxy prime and paint with a decent chassis paint?

 

[gray gables]

Why use POR if you are sandblasting? Paint over rust? Since the rust will be gone I assume, why not epoxy prime and paint with a decent chassis paint?

sounds like good advice to me,

 

[TN1776]

I did POR 15 after cleaning the frame, removing the grease, etc. Direct over rust and its held up well but as stated, if you're sand blasting it I'd say prime and paint, or even powder coat. If I were to do it again I'd prep the frame a lot more, smooth out that ugly factory weld spatter, etc.

 

[gray gables]

I did POR 15 after cleaning the frame, removing the grease, etc. Direct over rust and its held up well but as stated, if you're sand blasting it I'd say prime and paint, or even powder coat. If I were to do it again I'd prep the frame a lot more, smooth out that ugly factory weld spatter, etc.

ugly weld splatter, I wish I did that to mine also.

 

[u10072]

If it were me that was doing a frame again -- this is what I would highly recommend. Paint the frame with a good automotive grade acrylic enamel-- first prime with a matching etching primer. The thing that I would do is have the paint store make you about 2-3 spray cans of the paint you are using on the frame and under side of the body. Reason being that you will almost undoubtedly change something after you get it all assembled-- whether that be bolt or weld-on or just scratching the hell out of something. Having the matching paint color and matching quality would be really nice.

 

[TN1776]

Also if you do still go the POR-15 route, top coat it as its not UV stable. Not a huge concern under a rig but if it is going to be parked outside (and if you are super type-a) the frame ends that are exposed will fade to a chalky color and its ugly. Mine's garaged so its not a huge concern, just tossing ideas at you.

 

[73azbronco]

From what I learned talking to POR technician, unless you have some small amount of rust on the frame, POR will not stick well to a sand blasted and totally clean frame. You need to chemically etch the metal after sand blasting to give the POR a bite with their metal ready.

That's why I went and etch primed and single stage painted my frame, came out nicer than I thought it would. Please make sure you have everything done on the frame build wise like shock hoops or steering box beef up before painting.

See my frame link below.

 

[allenfahey]

You do realize you should not apply any paint directly over top of etching? If you etch it you must then seal it and then apply paint. No sanding of the etching or sealer is required just wait for it to flash off.

The POR "etching" some are referring to is just zinc phosphate in which POR says to rinse with water (same as Dupont 5717S) then apply the POR. For bare rusty metal after sandblasting it's a good idea to treat the metal with zinc phosphate prior to etching also for optimum corrosion protection.

 

[lowbush]

If I had it to do over again I would have pulled the rest of the stuff off of the rolling chassis that I built on and I would have had the frame galvanized. You should really consider it, if you are down to a sandblasted frame. I really wish I would have done it to mine.

 

[spap]

As stated poor 15 needs a rough service. To adhere. Powder coat would look good.
Weld spatter you guys just have weld spatter. I had several pieces of welding rod attached to the frame when I did mine. Haaa Late 70s was not a good time for car manufactures. The mess ups give it character worth another 500 bucks on the auction stand. Sorry for my rant.

 

[reynard101]

If I had it to do over again I would have pulled the rest of the stuff off of the rolling chassis that I built on and I would have had the frame galvanized. You should really consider it, if you are down to a sandblasted frame. I really wish I would have done it to mine.

X2. I sandblasted and POR'd. It came out ok. Definitely could have been better. But I keep saying that I'm going to four wheel this thing when I'm done - so POR will be easy to touch up if I feel like it. Can't touch up powdercoating.

 

[66broncofan]

I used KBS coatings after I got my frame sandblasted. KBS says a sandblasted frame is the ideal surface for it's product. I used rust seal and then Black Top.
Came out just fine! Make sure you wear your respirator etc...

 

[broncojo]

I sand blasted then went with an epoxy primer, then an enamel topcoat. I've done several vehicles that way and have been happy with that.

Another question why etch a sandblasted frame, I thought that sandblasting was a form of etching the metal. At least that is what I have gathered from the reading I've done over the years, maybe I'm wrong but I don't see the purpose.

 

[jmangi62]

I had my frame sandblasted then went with 2 coats of Rust Bullet which is "NOT" UV sensitive,then did 2 coats auotomotive enamel,came out great,and I can touch it up after my mods(shock hoops,radius arms,new trans xmember).Jim

 

[allenfahey]

Another question why etch a sandblasted frame, I thought that sandblasting was a form of etching the metal. At least that is what I have gathered from the reading I've done over the years, maybe I'm wrong but I don't see the purpose.

Etching is a sprayable product used prior to spraying primer or sealer. Good etching has a bit of acid in it to adhere to the bare metal. You can either spray etching or epoxy for optimum corrosion protection. Never apply epoxy overtop of an etching unless the TDS (technical data sheet) says you can. 99% of them you can't.

 

[Crawdad]

I had my frame galvanized for $100 locally. They normally don't do this type of work but they were nice enuff to do it. The process involves hours in the acid bath to get rid of rust and gunk. The acid bath does not get rid of weld slag or serious paint buildup. Not the prettiest job on the outside (chk out my 77 build for pics) but the inside was totally worth the $100 as it's coated very well. I was planning to do the 3 Step KBS System. It's around $100 and can go over the galvanize coating, but it's an all weekend job so expect lots of labor. During the galvanizing process there were a few chitty spots (I thought the acid bath would remove EVERYTHING!) so in order to fix I asked my sandblaster to sandblast just those areas that look like chit. He wanted to charge me $90 per hour which wasn't bad I guess. But he told me that he could powder coat the frame for $250 total. So really at this point I don't need the KBS paint with all the labor and time involved. So for roughly $350 I will have the inside galvanized and exterior galvanized, lightly sandblasted and powder coated. For the money I think it will be a good investment considering all I gotta do is drop it off and pick it up and I have the rest of the weekend to break something else. In about three weeks my frame should be back from the powder coater and I can start building!

 

[wepuckett]

I have read through this thread and from what I can tell I can sum it up to either sandblast and use the kbs painting system on the frame or sandblast and powdercoat the frame.

Are there other options I am missing to get the frame treated and taken care of?

 

[66broncofan]

I have read through this thread and from what I can tell I can sum it up to either sandblast and use the kbs painting system on the frame or sandblast and powdercoat the frame.

Are there other options I am missing to get the frame treated and taken care of?

I would not powder coat as it limits your future modifications like shock mounts, spring perches, cross bars, power steering frame reinforcement etc... My vote sandblast and KBS or just paint it. I personally did the sandblast and KBS and brushed it on. Looks good and has already allowed me to make a few repairs / modifications and just re-coat with KBS.

 

[Crawdad]

I have read through this thread and from what I can tell I can sum it up to either sandblast and use the kbs painting system on the frame or sandblast and powdercoat the frame.

Are there other options I am missing to get the frame treated and taken care of?

That sounds about right if you are wanting to go that far with your frame. It will come down to cost in your neck of the woods.

I'm going with powder coat on top of my galvanized frame. The galvanizing process did wonders inside the frame, not so pretty on the outside though. I'm finding this choice to be less time consuming and less heartburn compared to the KBS 3 Step painting. All I do is drop it off and pick up in a few days, then it's done. It would take me a good two full days to paint over a newly sandblasted frame with the KBS system. The down falls to powder coat is that you really cant modify the frame without ruining the PC finish. I plan to keep mine stock as possible, but I did reinforce the PS box area and that was done prior to galvanizing. I do expect chips in the pc as a result of rocks but some touch up paint should fix that. If you plan to modify the frame in the future then I'd go with a paint of some sort.
Advise I can give you would be to call some of these well-known bronco restorers. That's how I got the idea of galvanizing my frame, then use the KBS 3 Step paint system on top of it. That was my plan till my sandblaster/ powder coat guy said he could PC over the galvanized frame. I need to get off my lazy azz and take my shiney silver frame to him to PC!