Filler primer

[ozzyo]

Hello all,

 

a few post back there was mention about using Fairy liquid for cleaning kits before painting. I don't know if anyone has tried to see if it's true or if it's a myth. So I decided to give it a go on the piece of brass that I tried out the filler primer on.

 

It was washed in hot water and Fairy liquid and given a bit of a scrub with a paint brush. Then it was rinsed off in hot water once and then put on a radiator for one hour to dry. Then left to cool down. The first side masked off for the gray etch primer to be applied. This was applied and left in the spray booth for 1/2 an hour at 30 degs.

 

The gray was then masked off using a post it note as the primer would still be soft and I didn't want to pull any off. On this side I was going to use Halfords red primer, so I thought it would be better for it to have a bit of help with the filler primer to help it stick.

 

The finished article, this is now on a radiator to harden the primer off. It will be there for 24 hours, as with most central heating systems it will on and off over this time. The time it's on is approx 8 hours. The two longest times are 3 1/2hours and 2 hours.

 

After that I'm going to do some tests.

 

OzzyO.

[ozzyo]

Hello all.

 

in my last post in this thread you will remember that I was doing an experiment on the effects of using Fairy washing up liquid for cleaning brass and this was the test piece.

 

Well I have done the tests, OK, it may not be as scientific as some of yous may have come up with! All it involved was scraping a curved scalpel blade along the brass sheet, the first one was with light pressure, the second one with moderate pressure and the last one with quite a lot of pressure.

 

OK, some of yous may say that the etch primer had an extra 1/2 hour to dry, but the Halfords primer had the benefit of having the masking tape stuck down to the full face of the brass, so that may have taken away some of the lanolin from the surface.

 

The brass is now in some cellulose thinners to take off the primer so I can run it again but using red Cillit Bang as the cleaner. I will also grit blast the brass for the next one. The next time I will apply the Halfords primer first.

 

At the moment I know what I'm thinking.

 

OzzyO.

[ozzyo]

Hello all,

 

the test piece is out of the cellulose thinners and cleaned up, first the cellulose was wiped off and the piece was grit blasted.

 

Then it was washed in red Cillit Bang and rinsed in hot water. Then dried on the radiator, then left to cool, the L/H side was masked off then the Halfords red primer applied and left in the spray booth at 30 deg. for 30 mins. Then the red was masked off and the etch primer applied. This was also left in the spray booth for 1/2 an hour. Then hung on a radiator for 24 hours. So I wont be able to do the second test until tomorrow.

 

I still think that I know what the outcome will be.

 

OzzyO.

[ozzyo]

Hello all,

 

as yous know I have been doing some tests with preparing brass before applying primer. I will tell you now I got a bit of a surprise.

For completeness I'm including some photos that I've used before.

The brass test piece after grit blasting and washing in Red Cillit Bang and drying for approx one hour.

 

The two primers applied, the Halfords red was applied first and left for 1/2 an hour in the spry booth at 30degs and then masked off using a post it note, then the etch primer, as I was running out of time it went straight onto the radiator for 24 hours. Then left to cool.

 

Then it was onto the scrape test. The top one was light, to get a mark, about the same pressure as the medium on the first piece, the second one used about the same pressure as the heavy on the first piece and the last one a bit more. The top scrapes were from the grey to the red, the second set of scrapes were from the red to the grey and trying to apply the same amount of pressure as the first scrapes.

 

The first test piece.

 

Conclusion;

 

on the first piece the brass had been prepared using wet'n'dry running along the brass from L to R and R to L so the scratches would run the same way as the knife blade, maybe I should have gone up and down on this one!

 

On the second one this is where I got a bit of a surprise, as both primers performed very near the same, it was not as marked a difference as on the first test. I think that the main part of the prep. work that made the difference was the grit blasting and not the cleaning agent.

 

So short of doing a third test using grit blasting and Fairy liquid, I would say if your happy with Fairy keep using it, but for the best grip to the surface have it grit blasted.

 

If you have any thoughts on this please post them as two heads are better than one, and no question or suggestion is daft.

 

I have thought all this out by myself and the conclusions are my own thoughts so any input would be appreciated.

 

OzzyO.

 

PS. I'm still going to use etch prime even if it costs a bit more.

[ozzyo]

Hello all,

 

I take it due to the lack of replies to my conclusions that most of yous agree with my conclusions.

 

If not please reply.

 

OzzyO.

[Bruciethefish]

Grit blasting is a brilliant way to prepare metal surfaces for painting, as long as you have the equipment for doing it yourself... Last time I had someone blast a couple of loco bodies that had been painted with a tar brush, it cost me twenty quid, & that was mate's rates...

[ozzyo]

that had been painted with a tar brush, it cost me twenty quid, & that was mate's rates...

 

Bruce,

 

thats not to bad for getting the paint off (£10 a loco, I charge more), or did you do a partial strip first?

 

Going back to what I said about charging more I may grit blast the loco 4 or 5 times during the build.

 

OzzyO.