- Joined
- 31 Mar 2012
- Messages
- 56
- Reaction score
- 3
- Country
I have been doing some testing already so its not entirely from scratch.
For the most I use wire wheels and paint removing pads on the angle grinder, though not a big fan of this it does work.
The problem is getting into the corners. For smaller edges where I may end up welding I can do this by hand and isn't a big issue.
In general I am looking at preparing for paint - so its not entirely important to remove the (flash) rust layer, just any loose rust and paint.
I would have thought sand blasting would have worked better on removing paint over rust, though I'm guessing the difficult parts are where the primer has reacted with the surface. I use phosphate primers (red oxide mostly) so a light rusting is okay.
So I decided to have a look at sand blasting.
First attempt with the cheapest gravity fed gun and very dry sharp sand, didn't really do much. Though would remove the light rusting which im not in need of removing. Modified the gun as well to not block up and feed better with no luck.
Then I moved onto aluminium oxide(60-80 grit) and glass bead with a different "gritblasing gun" SB3 all from Clarke.
People have said about needing a "more powerful compressor" but the power is really only going to help with the recharge rate? Even before I lose some air capacity/pressure I don't seem to be getting any better results than removing the light rust layer over the top of millscale. I am running from 120psi - I shouldn't need higher? The guns suggest 80-100psi. I had a go at connecting it to a neighbours much bigger workshop compressor with similar results.
Then I tried an add on for my pressure washer (135bar, so mid to low sized), which worked just as well as the above but really next to little effect on paint/primer.
Where am I going wrong? If at all?
For the most I use wire wheels and paint removing pads on the angle grinder, though not a big fan of this it does work.
The problem is getting into the corners. For smaller edges where I may end up welding I can do this by hand and isn't a big issue.
In general I am looking at preparing for paint - so its not entirely important to remove the (flash) rust layer, just any loose rust and paint.
I would have thought sand blasting would have worked better on removing paint over rust, though I'm guessing the difficult parts are where the primer has reacted with the surface. I use phosphate primers (red oxide mostly) so a light rusting is okay.
So I decided to have a look at sand blasting.
First attempt with the cheapest gravity fed gun and very dry sharp sand, didn't really do much. Though would remove the light rusting which im not in need of removing. Modified the gun as well to not block up and feed better with no luck.
Then I moved onto aluminium oxide(60-80 grit) and glass bead with a different "gritblasing gun" SB3 all from Clarke.
People have said about needing a "more powerful compressor" but the power is really only going to help with the recharge rate? Even before I lose some air capacity/pressure I don't seem to be getting any better results than removing the light rust layer over the top of millscale. I am running from 120psi - I shouldn't need higher? The guns suggest 80-100psi. I had a go at connecting it to a neighbours much bigger workshop compressor with similar results.
Then I tried an add on for my pressure washer (135bar, so mid to low sized), which worked just as well as the above but really next to little effect on paint/primer.
Where am I going wrong? If at all?
