Bill, you are very correct in your observations, a secondary cleaning
operation is needed on certain items. Tapped bolt holes must be cleaned out,
along with external bolt threads, or severe galling will occur upon
installation of the fasteners. Glass beads are so fine that a visual
inspection will not do it. I use cylindrical brushes, liquids, and air to
clean threads, and quite often, run a tap through, just to be sure.

RJ

"William Cavers" wrote in message
...
I've been lurking here for a while and I would just like to add one
comment. I wouldn't allow anyone to use a blast cabinet for doing intake
manifolds. When I was working as a mechanic we let a fellow use the
cabinet to do an intake manifold and he didn't clean it properly and the
glass beads destroyed the engine. Naturally he blamed us.

If you do bead blast an intake manifold it needs to be cleaned several
times with hot soapy water. Cleaning with solvent, as in a parts washer,
won't work.

Just my .02. I should just add I think this is the best group on the
internet, I've learned a lot while lurking. Can't wait to get into my new
shop and start making chips again.

Regards

Bill


Backlash ) wrote:
: Harold has covered a lot of the finer issues associated with a blasting
: cabinet, so what I'll say is YES, YES, HELL YES, get a cabinet. If you
are
: into any type of refurbishing activity, It will be the best money you
will
: ever spend. Using glass beads, I use mine for everything from mill scale
to
: cleaning .014 carburetor jets and emulsion tubes for motorcycles.
Aluminum
: oxide for heavier rust and such. There are 2 cabinets, one is 32" wide,
and
: the other is 48" wide. Both have dust extraction systems with bag
filters. A
: pair of 5 hp compressors drive the units, to insure continuous use. A 2
hp
: is on standby if needed. Side money can be made by blasting things for
other
: people, such as aluminum intake manifolds and such. ($15 bucks, 15
minutes)
: One cardinal rule......Items must be dry and oil free, or you'll clog
your
: system.

: RJ

: "Harold & Susan Vordos" wrote in message
: ...
:
: "The Hurdy Gurdy Man" wrote in message
: ...
:
: I've been thinking about purchasing a small and inexpensive (Harbor
: Freight, to be precise) sandblasting cabinet but as I've never used
a
: sandblaster I'm wondering if it'd really be what I'm hoping. It
: probably
: wouldn't see so much rust removal duties as it would the removal of
mill
: scale from hot rolled steel items like angle iron and flats, but I
was
: hoping it could also be used to achieve nice matte finishes on
steels,
: aluminum, and plastics depending on the abrasive used.
Traditionally I
: rely heavily on things like wet-dry sandpaper and those abrasive
plastic
: Brillo-esque pads on the end of an angle grinder, but it seems like
a
: sandblaster would be more efficient and do a better, more uniform
job.
: Is
: this going to be the case? Or am I really going to be asking too
much
: of
: a Harbor Freight sandblasting setup? I suppose I could get one
: someplace
: else instead, but money's tight and I'm not planning on using the
: equipment too heavily anyhow. Would this sort of device do the job,
or
: should I be looking to other methods?
:
: You're on the right track where improving surface condition of
materials
: is
: concerned. Sand and bead blasting can leave very nice patinas,
depending
: on the media chosen and the pressure at which they are applied. In
: reality,
: you'd need a few different medias to accomplish a wide variety of
: finishing.
: Some are even non-destructive, such as walnut shell blasting.
:
: There are a couple considerations for you. One is the size of the
: cabinet. If you buy a small one you're going to find it is too small
: unless
: you are restricted to model type work. My cabinet will accommodate
an
: item
: that is 26" long and I consider the cabinet too small for many of the
: things
: that I'd like to blast. While pieces may fit inside the cabinet, it
: isn't
: always easy to blast them end to end, even when turning them over and
end
: for end. As items get longer and wider it gets more difficult to
access
: them with the gun.
:
: The second thing for you to consider is the amount of air you'll need.
: I
: run a Quincy compressor, two stage, rated at 19.3 cfm @ 175 PSI.
My
: cabinet can keep the compressor running almost continually. If you
are
: desirous of blasting an item without interruption until it is
finished,
: you
: might give the size of compressor you'll need considerable thought.
:
: There are economical ways to get around some of the issues. You can
: build
: your own cabinet if you have any welding capabilities, and use a
squirrel
: cage blower to evacuate the dust from the cabinet instead of using a
: vacuum
: cleaner. I have used both systems and prefer the squirrel cage blower
by
: far over the vacuum cleaner system. Your circumstances may prevent
going
: that direction, however, so give that some thought before making a
: decision.
: I live out in the country with no immediate neighbors so the dust is
not a
: problem. The vacuum systems are intended to be used with inside
: discharge,
: but I found the filtering system way too restrictive and time
consuming.
:
: I strongly encourage you to get the setup. You'll be surprised at
how
: much
: you'll use it if you have it.
:
: Hope this helps~
:
: Harold
:
:



--
William Cavers
Department of Engineering Mathematics
Dalhousie University
Halifax, NS
(902) 494-6120