Bench suction

Hi Folks,

I have a dental lab tech friend who solved the problem of
suction at the bench rather cheaply. There is a vacuum cleaner
for sale that is called a Rainbow brand. They are expensive
when new, These vacuums filter the incoming ‘dreck’ through
water and there is very little that escapes out of the exhaust.
Watch the local ‘Penny Saver’ type adds for a used ones or garage
sales are also another good place to find them. They can be
attached to a commercially made polishing cabinet made by Aqua
Tech, or a screen covered ‘fishmouth’ from Coe Indusrties, or a
homemade receptacle. These machines really suck…and I mean
that in the nicest sort of way.:slight_smile:

Regards,

Skip

Skip Meister
@Skip_Meister
N.R.A. Endowment &
Certified Instructor
in all disciplines
Certified Illinois D.N.R.
Hunter Ed, Instructor

   I have a dental lab tech friend who solved the problem of
suction at the bench rather cheaply.  There is a vacuum
cleaner for sale that is called a Rainbow ... These vacuums
filter the incoming 'dreck'     through water and there is very
little that escapes out of the exhaust. 

Skip -

You are soooo right !! I had one for years and loved it - it
finally bit the dust after 14 years of dealing with Husky fur
and construction dust (old house renovation type). I wish you
could find these in stores or catalogues, but you can’t - they
are only sold door to door. They are worth their weight in gold
and if anyone finds one - don’t let it get away - thinking about
it now in light of what you said, it would be perfect. The
collection mechanism regularly needs to be emptied, and I always
dumped it outside to let it dry out and then bagged it. Using the
machine on the shop floor would make it fairly simple to look for
lost stones in the dried out clumps or to send these clumps to
the refiner along with other scraps for recovery…great
idea !!

Laura Wiesler
Towson, MD.

Hi Laura,

Look in your local neighborhood ‘sale’ paper. The ones they
call ‘The Penny Saver’ or some such name, often given out at
local stores or in many cases delivered free to your house. I
have seen them for sale several times.

Skip

Skip Meister
@Skip_Meister
N.R.A. Endowment &
Certified Instructor
in all disciplines
Certified Illinois D.N.R.
Hunter Ed, Instructor

There are several new vacuums on the market which have what they
call “cyclone” action. They do not have disposable bags, but
rather have a clear container that the debris cyclones into.
This would certainly enable you to sort through debris for lost
stones etc. They supposedly pick up the smallest particles
possible and have those HEPA filters for allergens. Both Hoover
and Eureka now market these machines in all of the major discount
stores.

Interesting solution to an old problem. Just one
concern…what of the constant noise??? Those things
(especially the older ones)are noisey! Does anyone know of a
source for a quiet, effective and REASONABLY priced unit?

Steve

I second the motion. The rainbow is a great vacuum, had one for
over 18 years. True, you can’t find them in stores per se. Try
the vacuum repair shops. They get them in periodically, renovate
them, and then put up for sale again. Even used ones aren’t
cheap. But they are good machines !

Jan Fouts
Honolulu, HI

Hi Steve,

I have an Aqua-Tech unit that I use, It works on the same
principle and is very quiet. They have a plexiglass cabinet
which you can also purchase, I have one and it works great.
These units are sold by Dental Lab supply houses. I got mine at
Zahn Dental Supply. I don’t have their number handy but it is
an 800 number, so call 800 and get it from them.
Zahn is a really well stocked supplier and if you need help they
will bend over backwards to help. Get their catalog, because
some of their prices are better than jewelry suppliers. Their
’house’ brands have proven to be every bit as good as the name
brands.

Regards,
Skip

Skip Meister
@Skip_Meister
N.R.A. Endowment &
Certified Instructor
in all disciplines
Certified Illinois D.N.R.
Hunter Ed, Instructor

     Interesting solution to an old problem.  Just one
concern....what of the constant noise???  Those things
(especially the older ones)are noisey! Does anyone know of a
source for a quiet, effective and REASONABLY priced unit?  

The newer models mentioned (and they aren’t inexpensive) are
relatively quiet. Wouldn’t an exhaust fan (quiet one) be a better
choice and last longer? I spoke with our “heating and
airconditioning” specialist, and I’m having an exhaust system
installed for around $800. This will include a “surround” for my
soldering area which will exhaust to a far wall . . . on the
other end of my work area. He claims that this will reduce the
noise. The fan being used will be the kind that is being used in
new construction, and is supposed to be able to exhaust several
bathrooms at one time. AND this exhaust will not remove too much
of the internal air (which may cause the carbon monoxide fumes
from the furnace and/or water heater to re-enter the house.)
I’m assuming that this system will last quite a long time!

On my polishing machine, I have a fan with a filter. The filter
needs to be cleaned often and changed at least every couple of
weeks. I add a “dust collecting” type filter to the furnace type
filter to reduce the black dust caused by the bobbing/polishing
compounds.) The “dust collecting filter” is what is used for air
conditioners . . . I cut it down and tape it to the other filter.
It’s not inexpensive to do this, but I feel it is well worth
it.

Here’s another approach you might try. You’ll end up with about
the same thing as the Rainbow, but it will be lots cheaper.

I use an old (20+ yr.) Craftsman wet/dry shop vac. The entry
hole the hose attaches to goes directly into the tub. If you’re
going to dedicate the vac to the bench grinder/polisher, most
shop vacs can be modified to work with a water bath very easily &
inexpensively.

The small end of the wand is usually the same size as the end of
the hose that connects to the vac. This small wand end usually
will fit the inlet hole of the vac. Most inlet holes are in the
top cover of the vac & go straight through into the tub. To check
hole size, remove the top cover. Empty the contents of the tub
into the trash. Try to insert the small end of the wand in the
inlet hole from the inside. If it fits you’re in luck, if not,
back to the drawing boards.

1. Assuming it fits, draw a line around the wand where it
meets the bottom of the top cover. 

2. Remove the wand. 

3. Replace the top cover on the vac. 

4. Insert a tape measure/yard stick through the inlet hole
until it touches the bottom of the tub. Note the measurement
at the bottom of the entry hole. 

5. Transfer this measurement minus 1 inch (for starters),
(e.g.. noted measurement 14 3/4 -1 = 13 3/4 in) to the wand
with the mark. Measure down from the mark. Cut the wand off
at this point. 

6. Remove the top cover from the vac. 

7. Insert the cut off portion of the wand securely into the
inlet hole from the bottom of the cover. 

8. Fill the tube with water to a depth of 2- 3 inches. 

9. Replace the top cover with the cut off portion of the
wand extending down into the water from the inlet hole. 

10. Turn on the vac before connecting the external hose. 

11. A bubbling/guggling sound should be heard & the exhaust
vent should be exhibiting approximately the same volume of
air as before the modification. The exhaust air should not
contain any water mist/droplets. 

12. If the previous test was successful, connect the hose
between the vac inlet & the machine that's the source of the
dust. 

Check the tub after several times in the 1st hour of operation.
The water level may need to be increased/decreased for
satisfactory operation with your model of shop vac. Until you
become familiar with it’s operation, check the water level daily.
The reduced pressure in the vac tub cause the water to evaporate
faster than water left at atmospheric pressure.

The water should trap the majority if particulate matter. If
everything appears to be operating ok, you may want to replace
any filter your vac uses. The sludge & dirty filter can be
returned to your refiner if you want to recover any precious
metals.

If the wand from you model does not fit the inlet hole on the
inside, measure the hole dimensions, both inside & outside
diameters. Check your local hardware or plumbing store for
plastic plumbing fittings &/or pipe that may fit or be modified
to fit.

Check your hardware, home supply store or any store that sells
shop vacs. They usually sell hoses & hose ends of different sizes
and shapes that may make collecting dust from your ‘dust
generator’ a little easier.

If everything is a disaster for you, the worst that can happen
is you’ll have to vacuum while crawling on your knees (bg) or
spend about $5.00 for a new wand.

I’ve never tried these instructions; but if the need were
present, I’d not be afraid to. The only cautions I can think of
are: only use a large shop vac (over 2 hp with a large tub
(aprox. 16" high x 16" dia), if your vac uses a 3 wire power cord
(grounded cord), be sure to use a grounded outlet ( if the ground
prong is broken off, replace the plug or cord before proceeding)
& if you hear, see or smell anything unusual investigate the
source & correct the problem before continuing.

Here’s to cleaner air!

Dave