15 replies to this topic

[Mikey7094]

Hi

I have a small compressor for DIY paint spraying, and I was wondering if it was worth buying a sand blasting gun. You can buy them from Machine Mart for about £20. Has anyone used one of these? Are they any good? I need to get paint and rust of non-structural things like bonnet and bootlid, and also an old trailer that we have lying around that I'd like to do up. I wouldn't be using it for blasting a whole mini shell.

I've been using an angle grinder with one of those rust-removing discs that look like congealed bogies (not my words). It works but it's a bit tedious and the discs wear out very quickly. Would a sand blaster work faster?

Mike

[JustSteve]

I was going to ask the very same question, except I have a pretty large compressor. Would love to know what types of material are best for what jobs. Hope you dont mind the hijack

[lapider]

im the third person also intrested in this topic as im in the same situation but for alloys.

i asked my dad and he said he used to have one that was great for pin pointing slight bits of rust but he couldn't answer what it would be like for larger components.

in the aim of keeping costs down i was also planning on making a temporary blast cabinet out of mdf and plastic

[sledgehammer]

I wouldn't use sand as a shot blast abrasive

If you do - make sure you use proper clean air fed masks

as sand can cause silicosis (probably spelt wrong) if inhaled

http://www.silicosis...ting_risks.html

Edited by sledgehammer, 27 August 2012 - 01:13 AM.

[firstforward]

I wouldn't use sand as a shot blast abrasive

If you do - make sure you use proper clean air fed masks

as sand can cause silicosis (probably spelt wrong) if inhaled

http://www.silicosis...ting_risks.html

Everybody calls it sandblasting but nobody uses sand anymore.

I have one of these and yes it really clears away rust and crud but only really useful for doing small local areas, thing to remember is you must have no water in your air line and put up enough screening to contain the "blow off" of the grit media otherwise you will get a room full and or car full of unwanted grit........messy and expensive, I use plastic sheeting to contain and collect the media for re-use, not only this, you MUST wear a respirator mask and eye protection which after you add it all up, it costs some!!

If you want to do seriously larger areas up to full body I purchased one of these, and whilst I have never done a complete body it is more than capable I am sure.

[Jordie]

i hear they are ok for small parts. grab a plastic box thing from asda, approx 80ltr

place your part in the box when shot blasting, then the shot media is collected mainly in the plastic box. pour it out, sive it a couple of times and you can reuse the media.

if you dont, it will go everywhere, blow away in wind and become useless to reuse.

[donjarr]

You can also get soda blasters now, which from seeing a demo at a car show a year or two back look much better and nowhere near as harsh as grit blasting. Found this ( http://www.frost.co....da-blaster.html ) which is quite useful to look at.


I was going to write sand, but grit blasted my car when I was restoring it, however looking at websites things have move on somewhat as they do in 20 years and you can now buy complete kits (like the link in the other post) which mix and blast the grit from one tube, but it kind of depends on how much money you have to spend. If your pockets are deep then the larger canister type ones like in that link on the other post are great, but most need quite a high cfm to run, and always look at the max quoted as that will be for using it constant, and not stopping every five minutes to wait for the air pressure to build up.

When I did mine pre internet it was magazines and mail-order for stuff but as I was working on a tight budget and as I already had a compression just bought what was a spot blasting gun, ( like this http://www.machinema...5-spotblast-gun ) which is one that recirculates a small amount of grit, but took the attachments off to just used the gun as it was nice and compact and attached a grit feed hose to the old bag feed pipe. I mounted one of those plastic storage bins above the car as a hopper with a feed pipe going to the gun, and put a water trap in the air line as close to the gun as you can get is best. I had my main air line going to a water trap mounted low down near the floor, then a second air line from the trap to the gun. Being the Uk if its remotely cold or damp the water trap fills up really quickly so as a precaution used to set a timer set to one hour to check the water trap wasn't full, because it that fills up, and it goes down the air line you need to dry everything out before it works again.

Also while buying the main blaster is not that expensive you need to factor in the cost of the grit. A garage is best lined with plastic to catch the used grit, but before you can use it again it really needs sieving to remove the fine powder and a strong magnet passed over to remove the rust dust, or you find the fine rust dust sticks to everything as it's so fine, pluseach time you use the grit it breaks apart and found after about three uses, ait was to fine to be effective.

As for small parts you can get plans online to make a wooden blasting cabinet which is quite good, plus you can adjust the plans to suit the size you need. I made one from a picture I found to do all the smaller bits, and it was brilliant, as old rusty parts come out like new just needing a coat of paint.



Ps, always clean the area afterwards with something like acetone which removes any rust dust that may be sticking to the metal, or it will rust super quick.

[Mikey7094]

So they're not really up to doing panels (or trailers), then?

I guess collecting the grit would be the biggest issue.

And regarding the type of shot, do you need a respirator for using aluminium oxide grit? I have a mask for spraying paint (not an air-fed one), would this be good enough?

[tiger99]

If your mask is not air fed, it is probably not any use at all for spraying paint, in fact it may be positively dangerous because it gives a false sense of safety. I assume you are not using two pack, because otherwise you would be seriously and permanently ill, or dead. Filter masks do not remove solvents etc, at least not for long, so even with cellulose you will still be inhaling some very unhealthy stuff. Please don't ruin your health.

I would be seriously concerned about using a filter mask for blasting, as even though sand will not be used (dangerous, as has been adequately explained above, and also illegal), there will be fine particles of abrasive, rust, paint etc liberated, and fine particles of just about anything are bad for your lungs. Fileter masks only catch the larger particles, if they were fine enough to stop everything that matters they might seriously impede breathing. You can't get something for nothing. You really need advice from the supplier of the blasting media, who should know what is needed to use their product safely. They should know what grade of mask to use, and how often to change it. If you use a different media, you will likely need a different mask. Better to be safe than dead.

For small parts, a blasting cabinet or glove box solves the problem rather nicely, and minimises mess. I don't know if you could construct a polythene tent around and under the car, and manipulate the blast gun from outside the tent, to get much the same advantage when doing a whole car. It may be too awkward, or visibility might not be good enough.

I have been thinking about what I will need in my new garage, and as blasting equipment is likely to be wanted, I have been giving all the potential problems a lot of thought. I am hoping that the tent idea will work, otherwise I will go with an air fed mask. Almost certain to need that for painting too, unless a harmless but durable type of paint is invented soon. I see the real challenge will be to get the area clean enough after blasting to use it for painting too. And how do you get the area clean enough, after blasting an entire shell, to be able to build engines, or even more critical, hydraulic components? I don't know the answers yet, but I don't have space for two garages. Maybe the grit does vacuum up cleanly?

[sledgehammer]

Anyone thought of pressure washing with a sand attachment ?

this is a bit different -

[miniQ]

Anyone thought of pressure washing with a sand attachment ?

How much do you think that equipment costs? DB150 - $4999 LMAO (They make easily 200% profit on these things)

+ Compressor to run it (Which isn't shown.. that will cost a nice couple of grand) or a few hundred to rent

Edited by miniQ, 28 August 2012 - 04:42 PM.

[ludiluka]

d

Edited by ludiluka, 28 August 2012 - 04:43 PM.

[sledgehammer]

Anyone thought of pressure washing with a sand attachment ?

How much do you think that equipment costs? DB150 - $4999 LMAO (They make easily 200% profit on these things)
+ Compressor to run it (Which isn't shown.. that will cost a nice couple of grand) or a few hundred to rent

You miss read what I ment -

I used to own a steam cleaning company - we had warwick steam cleaners , with sand blast attachments on the lance head

the water draws the sand up the pipe with vacuum created by the head & will strip paint like this

http://www.ebay.ie/i...=item27c3194ee1

A normal 1000 psi pressure washer (which most of us have) would be sufficient to power this

the system in the video is different to what I was talking about (hence why I said this is a bit different)

Edited by sledgehammer, 28 August 2012 - 06:19 PM.

[miniQ]

Nope don't think it would be powerfull enough

If this was true everybody would be taking the paint off their own cars

Would just scratch and mess up the existing paint... would probaly take a few months to make any decent progress with such a system

Edited by miniQ, 28 August 2012 - 10:36 PM.

[sledgehammer]

Youve not used it then ...





will rip the paint off a car quickly

still leaves a mess , and has to be de watered quickly

with water and 1000+ psi , much more power than air

with more pressure and better abrasive , it will cut thru steel

I use water cut steel at work

Edited by sledgehammer, 29 August 2012 - 10:44 PM.