Technical Difference in Primers

The tech sheet did not give the first recommendation for top coat.
If it's older than 9 months I wouldn't take the chance. The ph will be off and will not perform like it's supposed to. Spend $70 more and I will send you a sandable solvent based epoxy, that is loaded with everything you could ever want in a epoxy.

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Thanks Mr. Guru for your time and help.I may do that. does that price include catalyst?

 

Yes and I will include shipping

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I am not sure which one we tested but I am assuming the LV is the low VOC and the LF is lead free. Both will work fine I'm sure without any noticeable difference between the two.

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I purchased a project truck that was originally sand blasted and sprayed in an unknown to me type primer with filler used in various spots as well. Where do I go from here? Do I have to sand the panels back to bare metal? Or can I scuff and apply epoxy? What about the filler? If it hasn't been top coated does it have to be removed?

 

Remove it all. The filler will have sucked up any moisture that was in the air and the primer very probably has as well and there could very easily be rust already starting under it. Why spend money and time on good product and put it over top of stuff that you have no idea what is under it or how it was applied. If you put a bunch of work and money into finishing this truck and then have the paint fail down the road you will regret not stripping it off in the first place. Do it right the first time.

 

K13 said it perfect.

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Thank you both.

 

Yep, that's the sad reality.
Hopefully there wasn't much value tacked onto the project for blasting, filling and priming because it's getting redone. Had the previous owner undertaken the redo then he'd be paying double. Sometimes those owners want to split that "double" cost with the new owner.

 

Revisiting this topic of primers once again. We have created a new solvent that encapsulates rust and can be added to our paint line to convert the full line to be direct to metal. It has corrosion inhibitors built it. Can be sprayed directly on the metal and does not leave a slimy film or anything like that. Completely compatible with any urethane or automotive grade enamel.
We created this due to the poor air quality of a lot of shops. We saw rust pockets form on cars 1 year after a paint jobs were completed. The cars were sandblasted, epoxy primed, body work then top coat. A small bubble (s) would form from 6 months to a year later, when the paint was scraped off at the bubble, rust had formed below the epoxy.
After testing films of paint, it was all due to poor air conditions from the compressor to the gun. Water in the air line (while priming) landed on the substrate (bare metal) this very little bit of water creates rust over time.
We then decided to create a direct to metal reducer to encapsulates any rust and push any moisture off the substrate that was present. But we didn't want to create a rust converter, just a solvent that could be sprayed directly to the metal, or if someone sandblasted a frame you could add this directly to your topcoat to convert the coating to be dtm. This is a temporary film, so a epoxy or any type topcoat is highly recommended to go on next.
Another huge benefit of this is, it can be added to clear coat and the painter can create a direct to metal clear coat that has corrosion resistance! Some of you have sprayed our lacquer clear and satin lacquer clear and YES you can add directly to that as well.
We are very excited to add this to our line, and is being added to our warranty and highly recommended before epoxy especially if you don't have a clean dry air supply.
Any questions about this just let me know.

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Interesting. Thanks for information.
-Dave

 

I have pulled my panel truck down and removed the body from the frame with plans to either get it dipped or blasted. Either way I was going to arrange to have it primed right away with epoxy primer and then do the metal and body work at my leisure.

Am I going to have to mix epoxy primer in a gun every time I weld or patch an area or is there an epoxy in a rattle can?

 

Use the best stuff you can afford - I'd never use a rattle can for anything like this - you want a great bind and epoxy primer (once mixed) has a limited pot life . . . so there is no way the stuff in the can is even close as far as what it is and how well it works.

Now - the above is just my opinion -- I don't/haven't used rattle can paint since I used to paint my bikes as a kid! LOL. But I have used just about all sorts of high quality autobody primers -- always, the best stuff I can find and afford as it is the BASE for everything else you do.

 

A quote by paint guru from a previous post, "

"
I've also heard good things about Spray Max 2k primer in a rattle can. It is a true 2k product that mixes in the can and is available from TCP global or Amazon. BUT, it's expensive and has a shelf life once you've punctured the mixing chamber and activate the can.

 

Very true! The 2k speed primer will last 4 days, it says 24 hours, but it does last a while. 1 can will do a decent sized area. At least 2 coats on a door. We sell a lot of spraymax. Everything in the line is top notch!

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How would this stuff compare to maybe ppg's CRE line?

 

Not familiar with the CRE line. Hard to tell, we have built based on customer needs. They tell us what they want and we build to spec. The one I was talking about is also semi gloss black so if you want to do firewall, chassis etc it matches the look without the need of a topcoat.

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That's sounds about the same.
CRE ( corrosion resistant epoxy) is from ppg's industrial line but most Autobody jobber supply houses that handle Ppg will carry it. CRE is very nice to work with, it builds excellent, fills pits and block sands like a dream. You Wouldn't think it was epoxy.

 

What is mix ratio and cost for the kit?

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CRE Mix ratio is 2:1 & 0.5 cut with acetone. 1 gallon primer and 2 quarts activator is about $150

 

Ok not bad at all, ours is 1;1 for $150. The white is a little less.

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Hey PG, great thread. Learned more in the past half hour than in the past 10 years of head scratching replies from paint store staff and vacuous manufacturer tech services responses.

I do rehabs on steel casement windows. I've built an electrolysis get up to strip them of all rust, glazing and paint. When they come out of the bath they are as rust free as you can get them. The bath gets into all the nooks and crannies. A light wire brushing or sanding is about all needed to have the base steel shining.

Steel casement frames are durable, but they do rust. I'm interested in discussing with you the best product you supply to be used on steel window frames being hit by all the myriad of conditions that 24/7 exposure to the weather (from coast to coast) shells out. I'm looking for quality and longevity. Whereas cost is always an issue, my clientele demands quality, and are generally willing to pay for it.

Please feel free to let me know of the products in your inventory that might best suit my needs. Thanks.

 

Yea I will send you a message. We can make you something based on dry time, durability etc. Also would like to check pH level before we recommend something. Thanks for the interest.

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Bumped into this thread as I was doing some research. Very informative, ty!
However I do have a question that I don't think was addressed in the 9 pages. I might have overlooked but here goes...

From what I understand certain epoxy primers contain isocyanate. Which, again from researching more, I understand is very very bad for you and one should use a full-face paint mask with a line feeding clean, fresh-air, that it also enters the body thru skin and that isocyanates are released when sanding the panels, even after primer fully cured.

I found certain manyfacturers offer an isocyanate free 2k epoxy primer (for instance https://www.motipdupli.com/nl/product/colormatic/aerosols-putty/filler/ipg-1324.html)

Would an isocyanate free primer still hold the characteristics as you described here in your original post: https://www.jalopyjournal.com/forum/threads/difference-in-primers.992953/

Also, I found a 2k acrylic (acrylic-urethane??) based primer (containing isocyanates) that is described to offer excellent corrosion protection and to work over bare metal: https://www.motipdupli.com/nl/product/colormatic/aerosols-putty/filler/ipg-1225/tm-1225.html But it offering corrosion protection goes against what you are saying in your original post? What am I missing here

Cheers

 

Doing the same research right now - most epoxy primers don't contain isocyanates. Epoxy primers will have the same properties regardless of isocyanate content, as isocyanates are usually in urethanes. Not sure why an epoxy would contain isocyanates in the first place, unless it was to make it dry faster. For the acrylic urethane primer, if it's listed as direct-to-metal with corrosion resistance, I'd give it a try. Epoxy is best for bare metal, but there are certain products that are exceptions. As always, read the technical data sheet and MSDS, those will usually answer these types of questions.

 

What if you are not able to sandblast the frame and still have rust in the pitting metal and unable to fully clean where the front springs sit?
Is it worth it to use a good quality epoxy?

Where do you buy Paint Guru’s paint?

 

I have had trouble finding red oxide colored 2k primer. Gray, black, cream... no problem. Red seems to have been, for the most part, passed over. Or maybe I'm looking in the wrong places.

 

Try Paintguru's directly, on where to get within their distrubribution network.

https://www.southernpolyurethanes.com/pricing
SPI has red oxide epoxy, I believe all of their epoxies have mix instructions to also use as a sealer.

 

I just did a search for this, for the underside of Les Popo, Southern Polyurethanes Inc. (SPI) has a red oxide epoxy primer.

 

The purpose of a primer is to prevent corrosion. What is the most powerful primer to prevent this ? The aluminum pigmented moisture cured single component is by far the most effective for preventing corrosion. Zinc phosphate epoxy primers will generally fail around 700 hours of salt fog testing. The moisture cured primer 7000 and beyond. epoxies you need 60° to apply it , some cases an induction time. Moisture cure 40 degrees, it's small molecular structure is great for adhesion. This resin is used in Gorilla Glue so you know it's sticks. Unfortunately when it was introduced to the Hobby it was changed from Mobay's original formulation. It's more of a concrete and wood floor sealer. When it came to the Hobby the powers-that-be, who never touched a car, said they don't want silver they want black , they're painting the bottom of their cars. So they changed the resin , the thinner and the pigment where was no longer airtight. Basically concrete and wood floor sealer. Here is a video I did recently .