Self Etch Primer SEM bs Rustoleum

[mgroleau2125]

Hello all,

I have been using SEM self etching primer for the empennage parts that need it. I recently came across Rustoleum Self Etching primer at Walmart for $7 a can. Vs SEM $34 a can. I also read a post a while back that “primer is primer” is this true?

If I rattle can the small parts, does it really matter which self etching primer is used? Anyone have experience in this?

Thanks!
PS I did a search but only found where people used Rustoleum paint for their panels.

 

[AlphaCharlieBravo]

Primers

Don't know if you have seen this.

Hope it helps in your decision. I used Napa 7220. It was 7 dollars when I started my build and 13 when I finished using it.

Arnie

 

[mgroleau2125]

Primers

Don't know if you have seen this.

Hope it helps in your decision. I used Napa 7220. It was 7 dollars when I started my build and 13 when I finished using it.

Arnie

I have not, thanks though. Seems like all self etching primer is equal in function. Varies in quality of spray pattern etc?

 

[PaulvS]

I have not, thanks though. Seems like all self etching primer is equal in function. Varies in quality of spray pattern etc?

A simple test for adhesion and durability is to spray a test piece. After it has hardened, apply some heavy duty self-adhesive Gorilla tape to the part, press it on thoroughly and then rip it off. Next, try scratching the surface with a coin and see how hard you need to press to scrape off the paint.
Further tests for corrosion protection would involve salt spray exposure, if you are interested in going to that much effort.

 

[mgroleau2125]

A simple test for adhesion and durability is to spray a test piece. After it has hardened, apply some heavy duty self-adhesive Gorilla tape to the part, press it on thoroughly and then rip it off. Next, try scratching the surface with a coin and see how hard you need to press to scrape off the paint.
Further tests for corrosion protection would involve salt spray exposure, if you are interested in going to that much effort.

Great! I’m going to try that. I do have a buddy that makes salt brine to put down in his parking lots he plows before it snows, and tis the season for that. I’ll try some scrap pieces with the different primers, and alodine that I have been reading bout.

 

[dwollen89]

I use NAPA 7220. Mainly because it shoots well and is pretty cheap. For parts that you’re not going to likely ever touch again, like inside the wings and tail assemblies, I just wipe with acetone, shoot and assemble. For inside the fuselage, I scuff with a maroon 3M pad, then wipe with acetone and shoot.

 

[Ironflight]

I have been using the Rustoleum Self-Etching for years on interior stuff - both top-coated (with Rustoleum) for interior cockpit parts, and bare (for things like tail one interiors, or the interiors of skins) with no problem whatsoever. I think it has now gone close to $10-$12 per can, depending on if you find a sale, or buy a case. Oh - I always scuff with purple or green Scotchbrite before I shoot.

While I applaud those who test with salt brine, ask yourself just how realistic that is for your aircraft….are you going to submerge it off the gulf coast for a year or more? . I know several long-time posters have hung samples outside for very long periods of time, which is really interesting science, but I’m not sure how that relates to the real world…..

 

[wirejock]

I use 7220 on steel or small parts I neglected to spray. It cures pretty quick. Napa is close. I do use SEM products elsewhere. They make good stuff.
Most parts are sprayed with P60G2 or Alodined.

 

[mgroleau2125]

I have been using the Rustoleum Self-Etching for years on interior stuff - both top-coated (with Rustoleum) for interior cockpit parts, and bare (for things like tail one interiors, or the interiors of skins) with no problem whatsoever. I think it has now gone close to $10-$12 per can, depending on if you find a sale, or buy a case. Oh - I always scuff with purple or green Scotchbrite before I shoot.

While I applaud those who test with salt brine, ask yourself just how realistic that is for your aircraft….are you going to submerge it off the gulf coast for a year or more? . I know several long-time posters have hung samples outside for very long periods of time, which is really interesting science, but I’m not sure how that relates to the real world…..

It’s a steal right now at my local Wally Mart. Thanks for all the info.