PRIMER for e-coated floor pans ?

GERMYS_72 · Oct 8, 2024

What primer is suitable to spray directly on the E-coated floor pans ? I have no intention of stripping the floor pans to bare metal to coat with Epoxy. Looking for suggestions on how to get a few decent coats of primer, then rubberized coating on the street side of the panel.

I have POR15 silver, and "Zero Rust", but if Rustoleum Auto primer from Walmart is adequate I'm happy to do that.

Screenshot 2024-10-08 at 10.33.45 PM.png

tpj71mach · Oct 9, 2024

I would rough up the e-coat with a red scotch-brite pad very well so whatever product you use adheres properly, first. I would recommend using an epoxy primer first, you do not need to strip down to bare metal to spray with epoxy primer. It is commonly used when the metal is stripped bare because it is a primer that can be applied direct to metal, not all primers are DTM. Por15 is also a DTM product so it can be applied directly to the e-coat or bare metal and rust without a primer, if you choose not to prime, even if you sand through the e-coat while prepping. I like Por15 because it will be a much more durable product and is chip resistant, although I always seal with epoxy first. The Por15 wouldn't need any rubberized coating over it , if you preferred the painted finish appearance. If you are not dressing and finishing the welds, then the rubberized coating will disguise some of the repairs.

GERMYS_72 · Oct 9, 2024

tpj71mach said:
I would rough up the e-coat with a red scotch-brite pad very well so whatever product you use adheres properly, first. I would recommend using an epoxy primer first, you do not need to strip down to bare metal to spray with epoxy primer. It is commonly used when the metal is stripped bare because it is a primer that can be applied direct to metal, not all primers are DTM. Por15 is also a DTM product so it can be applied directly to the e-coat or bare metal and rust without a primer, if you choose not to prime, even if you sand through the e-coat while prepping. I like Por15 because it will be a much more durable product and is chip resistant, although I always seal with epoxy first. The Por15 wouldn't need any rubberized coating over it , if you preferred the painted finish appearance. If you are not dressing and finishing the welds, then the rubberized coating will disguise some of the repairs.

Awesome. I also considered spraying the hell out of them with the Rustoleum Farm and implement Red Oxide Primer (similar to original Ford Primer) and saving the POR15 for other problem areas since it was $170 a gallon.

Sheriff41 · Oct 9, 2024

If you're going to use Rust-oleum and you have a compressor, buy the paint in the quart cans and get yourself a cheap (Harbor Freight) spray gun to apply it with. Follow the instructions on the can. It'll be cheaper and you'll get better coverage than from a rattle can.

GERMYS_72 · Oct 9, 2024

Sheriff41 said:
If you're going to use Rust-oleum and you have a compressor, buy the paint in the quart cans and get yourself a cheap (Harbor Freight) spray gun to apply it with. Follow the instructions on the can. It'll be cheaper and you'll get better coverage than from a rattle can.

Will do. Thanks Chuck

tpj71mach · Oct 9, 2024

You can use that I am sure, I am not familiar with that product but it says it has some weather resistance. Fortunately, ours cars are probably never going to see the elements they lived in for their first few decades of life ever again. I like to overkill, I seal mine up as best I can so they will last and I can drive them when and where ever I want. I just prefer a clean painted finish underneath even thought there is no need for it, just my OCD kicking in.

Fabrice · Oct 9, 2024

I would not use a rust inhibiter primer, simply because it's of no use since you will spray on top of e-coat, preferably roughen a bit so that all sticks good. The rust prevention is about being airtight, and the properties of these primers work only if in contact with the metal itself as they convert the rust into a passivation layer (big word to say oxygen won't go thru and oxide the metal) before drying up.
I would simply spray a good so called "wetonwet" primer and may be some paint or just a layer of epoxy in the colour you like.
I mean, spraying the rust prevention won't hurt, but it's not like it will do a thing on top of eCoat, and usually these products are more expensive but lesser primers than real and cheaper primers.

GERMYS_72 · Oct 9, 2024

Fabrice said:
I would not use a rust inhibiter primer, simply because it's of no use since you will spray on top of e-coat, preferably roughen a bit so that all sticks good. The rust prevention is about being airtight, and the properties of these primers work only if in contact with the metal itself as they convert the rust into a passivation layer (big word to say oxygen won't go thru and oxide the metal) before drying up.
I would simply spray a good so called "wetonwet" primer and may be some paint or just a layer of epoxy in the colour you like.
I mean, spraying the rust prevention won't hurt, but it's not like it will do a thing on top of eCoat, and usually these products are more expensive but lesser primers than real and cheaper primers.

Thanks for the detailed explanation. Can you say what product would be on the less expensive side of the wetonwet options ? What "cheap" primer would do the job ?

Sheriff41 · Oct 9, 2024

Keep in mind most primers other than perhaps epoxy primer will not provide protection. Primers are basically meant to provide adhesion between the paint and the surface, though some provide additional benefits such as high-build primer. If you're looking for protection you will want to spray a layer of paint or other product over the primer that seals the substrate.

GERMYS_72 · Oct 10, 2024

Sheriff41 said:
Keep in mind most primers other than perhaps epoxy primer will not provide protection. Primers are basically meant to provide adhesion between the paint and the surface, though some provide additional benefits such as high-build primer. If you're looking for protection you will want to spray a layer of paint or other product over the primer that seals the substrate.

Fabrice said:
I would not use a rust inhibiter primer, simply because it's of no use since you will spray on top of e-coat, preferably roughen a bit so that all sticks good. The rust prevention is about being airtight, and the properties of these primers work only if in contact with the metal itself as they convert the rust into a passivation layer (big word to say oxygen won't go thru and oxide the metal) before drying up.
I would simply spray a good so called "wetonwet" primer and may be some paint or just a layer of epoxy in the colour you like.
I mean, spraying the rust prevention won't hurt, but it's not like it will do a thing on top of eCoat, and usually these products are more expensive but lesser primers than real and cheaper primers.

It sounds like slapping on some Epoxy is still the best move here, even though it's not bare metal. Thanks

Don C · Oct 10, 2024

https://autobodysource.com/never-spray-an-e-coat-without-priming-heres-why/

tony-muscle · Oct 10, 2024

Don C said:
https://autobodysource.com/never-spray-an-e-coat-without-priming-heres-why/

Interesting on how to test if the e-coat is stable or not. From what I understand then if the part is not exposed to UV it doesn't matter.

Lazarus · Oct 10, 2024

I have had mixed results with those ecoats, for what it’s worth. On a floor I wouldn’t be terribly worried but it’s not always applied great; sometimes it appears to be added after the metal has already flash rusted. I am a big believer in the epoxy sealer either over the ecoat or bare metal.

GERMYS_72 · Oct 11, 2024

Don C said:
https://autobodysource.com/never-spray-an-e-coat-without-priming-heres-why/

Thanks. I read this post. It sounds like Epoxy Primer or Primer Sealer is the way to go.

PRIMER for e-coated floor pans ?

Help Support 7173Mustangs.com:

GERMYS_72

Well-known member

tpj71mach

Well-known member

GERMYS_72

Well-known member

Sheriff41

Well-known member

GERMYS_72

Well-known member

tpj71mach

Well-known member

Fabrice

Well-known member

GERMYS_72

Well-known member

Sheriff41

Well-known member

GERMYS_72

Well-known member

Don C

Fords Forever

tony-muscle

Well-known member

Lazarus

Well-known member

GERMYS_72

Well-known member

Similar threads

Latest posts

PRIMER for e-coated floor pans ?

Help Support 7173Mustangs.com:

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Fords Forever

Well-known member

Well-known member

Well-known member

Similar threads

Join the conversation!

Join today and get all the highlights of this community direct to your inbox. It's FREE!