Has any one made their own venturi sand blasting head to use on a water
blaster? if so any clues?

On Wed, 01 Dec 2010 00:55:34 +1100, F Murtz wrote:

Has any one made their own venturi sand blasting head to use on a water
blaster? if so any clues?

No, but I did have a proprietary sand blaster attachment for my (old)
pressure washer. Pretty much useless


--
The Wanderer

I may not have gone where I intended to go
But I seem to have ended up where I need to be.

On Nov 30, 1:55*pm, F Murtz wrote:
Has any one made their own venturi sand blasting head to use on a water
blaster? if so any clues?

No, but I have used the one for my presure washer. It works OK to
shift some sorts of green growing gunk, but it has no power for any
sort of mechanical work, de-rusting etc. It's also a pain to clear up
afterwards.

For cleaning metal, the only thing I've found useful is a pressure-pot
gritblaster. You can make these yourself (steel drum, pipe fittings)

F Murtz wrote:
Has any one made their own venturi sand blasting head to use on a
water blaster? if so any clues?

No, but some clues. They work on the venturi principle. High pressure
nozzle firing across an angled intake pipe. Output nozzle needs to be
hardened steel as a minimum, ceramic is best.

You need a big FO machine to effectively run a wet sand blaster. 200bar @
20 lts/min or above IME. They are a PITA to clean up after & suffer from
blockages if the sand gets damp.



--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On Nov 30, 2:25 pm, Andy Dingley wrote:

For cleaning metal, the only thing I've found useful is a pressure-pot
gritblaster. You can make these yourself (steel drum, pipe fittings)

that sounds cool - any links/pointers/info please?

Jim K

On Nov 30, 7:13*pm, Jim K wrote:
On Nov 30, 2:25 pm, Andy Dingley wrote:

For cleaning metal, the only thing I've found useful is a pressure-pot
gritblaster. You can make these yourself (steel drum, pipe fittings)

that sounds cool - any links/pointers/info please?

Searching for "pressure pot sandblaster" should show up enough to do
it. Don't be fooled by venturi or syphon designs instead.

You need a pressure-proof steel drum (full working pressure), so a gas
cylinder is the likely favourite starting point.

Weld on some legs as a raised stand and also some pipe fittings. 1/2"
steel pipe and full-bore ball valves (big handles, you'll be working
in gloves) At the bottom you need .a pipe fitting, at the top you need
another pipe fitting and the biggest screwed plug filler you can find.
You're making a big steel 90psi+ pressure vessel here, so the welding
has to be spot-on and you ought to hydraulic test it afterwards...

At the bottom you plumb a tee piece. One side is the output through
some heavy rubber hose and a steel pipe output nozzle (plain tube is
fine). Ideally buy some hard ceramic commercial nozzles and use
those. The other side of the tee is air supply, which comprises a hose
from the compressor, a second tee and two ball valves and then
connections to top and bottom. You have to fiddle the valves manually
to adjust air/sand flow rates. If you're lucky, you can replace these
with fixed pipe of exactly the right dimensions (probably after having
used prototype #1 for a bit) and use a single ball valve as an on/off
air valve. Tip: Use some flexy rubber hose to connect to the top
connection, it's much easier to assemble than rigid steel on a fitting
of uncertain alignment.

You _need_ big gloves and a hood (cheap face shield with a fabric hood
attached). You might like apron and full rig too. Leather welder's
jackets (cheap chrome leather) are woorth having.

Use grit, not sand, to avoid silicosis problems. Use the right grit
and change it between iron, aluminium, glass etching and plastics.

On Nov 30, 6:49*pm, "The Medway Handyman" davidno-spam-
wrote:

You need a big FO machine to effectively run a wet sand blaster. *200bar @
20 lts/min or above IME.

20 l / min @ 200 bar. Now that _is_ big!


I'd say about 30 l / min actually (but not quite that pressure) A
pressure pot can be used usefully with a 10l/min compressor, but
you're not getting the same sand delivery rate. If you have small
enough nozzles, you can even throttle back to a rate that allows
continuous running, still on a D-I-Y compressor. Bigger nozzles though
need enough airflow to keep the sand moving, so you're limited to an
intermittent duty cycle.

Andy Dingley wrote:
On Nov 30, 6:49 pm, "The Medway Handyman" davidno-spam-
wrote:

You need a big FO machine to effectively run a wet sand blaster.
200bar @ 20 lts/min or above IME.

20 l / min @ 200 bar. Now that _is_ big!

Sorry, when I said 'machine' I meant pressure washer :-)

--
Dave - The Medway Handyman
www.medwayhandyman.co.uk