What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Testing rattle can primers

lipper03

Builder RV14A & ZA750SD
Benefactor
While I’m waiting for my emp, I’m doing some testing of rattle can primers. Yesterday did my first spray coat of sem etching, sem ezcoat, and duplacolor self etching, after doing a scotch brite scuff then acetone rinse.

So far it seems the sem ezcoat is working well. It’s got a bit of gloss, can’t see a fingernail scratch after about 16 hours cure. Others can see a fingernail scratch, not to metal but can see marks.

All scratched to metal with a light screw driver scratch.

Dimpled a section at 16 hours, all were good. Rubbing underneath side with finger, sem etch rubbed off.

Seems winner so far is sem ezcoat.

Any others have similar results?
 

Attachments

  • 8E208E4E-500C-4BA8-BFD0-826D9506B04E.jpg
    8E208E4E-500C-4BA8-BFD0-826D9506B04E.jpg
    368.7 KB · Views: 153
  • E95213CE-D364-4606-8C67-BE3C47E8EC3B.jpg
    E95213CE-D364-4606-8C67-BE3C47E8EC3B.jpg
    256.6 KB · Views: 145
  • FCD4E914-DD37-4505-BBDF-5761B7D9F1D4.jpg
    FCD4E914-DD37-4505-BBDF-5761B7D9F1D4.jpg
    269.8 KB · Views: 139
The durability and scratch resistance greatly increases with a longer cure time. Think weeks and months, not hours.

Dave
 
At least.

While my RV-3B kit is taking far too long, I have noticed improvement in the durability of previously-sprayed SEM and zinc chromate/zinc phosphate rattle can primers over the years. It does get marred as I make progress but is easy to touch up. But it remains reasonably tough. SEM is a good product.

More recently, I've been using Stewart Ecopoxy epoxy primer, and like other epoxy primers, it's quite tough. Plus it's resistant to lacquer thinner, which the rattle can primers aren't. I've used it in the cockpit specifically for its toughness.

Incidentally, while it might be exacerbated by the small size of the RV-3 fuselage, I've observed that using white Ecopoxy makes the tailcone lighter and easier to work in. The sides and bottoms are the old zinc chromate but the top is the white. If I were doing it again it would all be white. I've painted the baggage compartment white, the seats white and the cockpit sides forward of the spar bulkhead, where it can't reflect on to the canopy, just for easier usage. The cockpit sides and bottoms which could reflect in the canopy are a medium dark gray.

Dave
 
While I’m waiting for my emp, I’m doing some testing of rattle can primers. Yesterday did my first spray coat of sem etching, sem ezcoat, and duplacolor self etching, after doing a scotch brite scuff then acetone rinse.

So far it seems the sem ezcoat is working well. It’s got a bit of gloss, can’t see a fingernail scratch after about 16 hours cure. Others can see a fingernail scratch, not to metal but can see marks.

As an engineer I love collecting data.
As others mentioned, paint takes time to reach full cure. I grew up only a mile from 3M headquarters and Research Labs in St Paul and remember paint samples that were years hanging outside to test durability and fade.
Test for chemical compatibility too. After several months see what different solvents will touch. And of coarse the biggest issue is compatibility with top coat system you plan to us. I think most of these self etching primers are pretty compatible. I was very happy with Marhyde and then PPG Concept over the top. Still bullet proof after 20 years looks like the day it was sprayed.

I've observed that using white Ecopoxy makes the tailcone lighter and easier to work in.

At the big airplane company all bays that are accessed for routine servicing are painted white for that very reason. Also helps to quickly identify fluid leaks.
 
internal prime only

Just for info, I'm using for internal parts only. I'm hangered in the Houston area, so want some extra protection, but not wanting to spend all my time priming, so trying the rattle can route.

External I'm going to have pro's do when finished, so they will external prime and paint with right systems etc (at least I hope, but that's a few years down the road).
 
Back
Top