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Grit blasting
Russell - 6/4/08 at 01:18 PM

The paint on my all-steel trailer is peeling away badly and it's rusting a lot. I want to give it a lick of paint before it gets too bad. The finish isn't critical because the thing is only used for trips to the DIY store and down the dump.

I've got a 2.5HP compressor (not sure of CFM) and a grit blasting air tool and I thought about blasting away the flaky paint before repainting. I remember using Nitromors on the underside of the trailer years ago to address the same problem and that was pretty cr4p to work with and it wasn't too effective either.

Anyone got any tips/do's/dont's before I have a go at this? Also, I haven't got any grit/beads so I wondered whether kiln dried sand would be any good?

Ta!

blakep82 - 6/4/08 at 01:22 PM

use a zinc primer. i was always pretty wary of how good they really are, but having painted my axle with it, any bits that chip off (which is a few at the moment, it will need to be painted again) shows the metal to be a nice healthy black colour underneath, so there's been some kind of reaction underneath

triumphdave - 6/4/08 at 01:23 PM

Dont use sand its a bit dodgey there is a thread somewhere on here about it.

blakep82 - 6/4/08 at 01:27 PM

hmmm, sand, silcosis or something you can get form getting sand in your lungs.

might be ok if you wear a proper mask though?

MikeR - 6/4/08 at 01:36 PM

recently re´read sand thread,basically its a real no no. verybad for you and youll need an air fed mask if you want to use it is my summary of the thread.

rusty nuts - 6/4/08 at 02:35 PM

Get a quote from your local blasting company, they will do a better job and its a damn sight safer.

zilspeed - 6/4/08 at 03:41 PM

There's nothing that a wire brush in an angle grinder (aka 'the tool' ) won't remove.

Grind a section clean, paint it.

Repeat until finished with a little overlap between sections to make sure.

Blasting is a real no no unless you live somewhere remote and on your own.

aerosam - 6/4/08 at 06:20 PM

quote:
Originally posted by zilspeed

Blasting is a real no no unless you live somewhere remote and on your own.


Or you have access to a large industrial grit blasting cabinet. Me so lucky!

Russell - 6/4/08 at 07:16 PM

Oo err. Well and truly put off grit blasting using sand!!! Revert back to plan A and use the wire brush then.

Thanks for saving my lungs guys!!

blakep82 - 7/4/08 at 12:28 AM

i still can't work out how i'm going to get all the paint off my chassis... i'd like to sand blast it. i've not got a blast cabinet to fit it in sandpaper would be a nightmare on my chassis... it would be rusty before i'm finished, don't kinow what to do

zilspeed - 8/4/08 at 08:01 PM

quote:
Originally posted by blakep82
i still can't work out how i'm going to get all the paint off my chassis... i'd like to sand blast it. i've not got a blast cabinet to fit it in sandpaper would be a nightmare on my chassis... it would be rusty before i'm finished, don't kinow what to do


Derust a section with your wire brush equiped grinder then prime it.
Overlapping the next section the next day isn't a problem.

blakep82 - 8/4/08 at 08:11 PM

quote:
Originally posted by zilspeed
quote:
Originally posted by blakep82
i still can't work out how i'm going to get all the paint off my chassis... i'd like to sand blast it. i've not got a blast cabinet to fit it in sandpaper would be a nightmare on my chassis... it would be rusty before i'm finished, don't kinow what to do


Derust a section with your wire brush equiped grinder then prime it.
Overlapping the next section the next day isn't a problem.


have you seen my chassis though?
i won't be able to get a grinder into most of it...

MikeR - 8/4/08 at 10:12 PM

lots of plastic sheeting and ali oxide then ????

(i've no idea of the health implications to ali oxide - although i am curious)

blakep82 - 8/4/08 at 10:24 PM

sorry about the picture size, think grit blasting mihgt be the only way...