Short answer:

For a single hand tool – Something rated at over 120 CFM (or 6hp) that you can use a 2.5″ shop vac style hose minimum.  A Metabo ASR35 works very well.   Also Rigid brand or big Shopvac brand vac falls in this category.  A cyclone seperator like “Dust Deputy” is a great idea for filter longevity.  Pricing is $200-600 range more for HEPA filteration

For 2 handtools – something 200cfm or greater with a big filter-  Little Red Ruwac is a great choice.

For large gas powered Walk behind saws and 220V Planetary Surface grinders- something 300cfm or greater with a 3-4″  hose inlet minimum for production type work.

Quality of segment:

There are several levels of quality in the diamond segments themselves.  Premium, standard and economy.  This has to do with the manufacturing process and the diamond content.  Joe Due stocks and sells premium (Best Quality) diamond blades we can buy.  We do this to offer the best product we can and provide consistant performance and expectations in the tools themselves.  We can and have sold the standard quaility blades per customer request.

Many other companies will try sell you standard or economy quality blades (and may or may not tell you thats what they are) because they can sell them cheaper (we could too) or make more money on them and it is very difficult to visually see any difference in the segment itself.  Segment height does not have anything to do with quality of the segment itself, but does affect pricing.

Its always possible the lesser quality blades could be a better value at life per dollar, depending on many factors.  Also one persons “premium grade” may not be equivant to another.

The bond consists of the material matrix that holds the impregnated diamond segments within the segment itself.  The matrix needs to wear away at the correct rate to keep the diamonds exposed and thus keep cutting, but not too fast to prematurely wear it out.  The bond of the Blade should correspond to the hardness of the concrete for best life, performance and production of the blade.

On really hard cured concrete (river rock), use soft bonded blade.  a medium or hard bond will glaze over and stop cutting.

On soft or green concrete (seashells or sand) use a hard bonded blade for the best life.  The medium will wear out prematurely, the soft bond wont cut.  Tuckpointing blades are normally hard bond by default because mortar is a soft abrasive material.  Asphalt blades as also hard bond.

Most general purpose blades are Medium bond.  Soft and hard bond blades are less popular, more job specific, lower volume and typically cost more than the Medium bond counterparts

Grits in cupwheels correlate to how big the diamonds are within the segment.  This system is very similiar to that of polishing pads.  Grit is independant of Quality or bond. The gritted cups we carry are a medium bond.

Most Cupwheels are a “normal” 30/40 grit.  This a good performing general purpose type grit which floor coating can stick to and give average aggressive cutting.  30/40 has long been the industry standard.

More aggresive cutting wheels would be a 20 grit or 18 grit as some vendors carry.  The bigger diamonds grind faster, leave bigger scratches and are well suited for “hogging down” high spots where a smoother finish isnt warranted.

Higher grit, less aggressive and smoother finish cupwheels are available.  80/100 or 170/200 grit are available through us, other vendors may have higher numbers than that depending on size.  These cupwheels are usually used to step up on edging from 30/40 for polishing floors so as not to burn through many 50 grit resin pads to get to a 100/150 stage.

For thicker coatings, the PCD (poly crystaline diamond) cupwheels work well for initial take off.   They have super hard teeth that chew through tough coatings.  disposable Abrasive disks (Zec and Taz) are an inexpensive option also.

You would remove 85% of the coating with those and come back over it with a diamond cupwheel to prep the concrete for a new coating as needed.

Typically, cupwheels with fewer segments  (12 seg turbo) and/ or oriented in a pointy fashion (arrow style) fair much better at one stepping coating removal and concrete floor prep.  The more segments or different segment style configuration may work fine, but production may be slower, even though blade life may be extended (say a 24 segment turbo)

For using our Dust avenger 005 and Dust mizer 005 Kits YES you can use a blade up to 5″ diameter because the shroud is designed to allow enough clearance for it.

If you are using the factory metal blade guard then only the blade diameter the grinder is rated for can be used.

An Angle grinders inch rating is based upon the amps (power) it has and RPM it turns.  5″ and 6″ angle grinders will run at a lower RPM so the OD blade speed remains at acceptable levels.  5″ and 6″ grinders typically have higher power rating to compensate for the more energy to turn a bigger blade and also for cutting deeper etc.

Because of the stress a grinding cupwheel and deep/ wide cutting saw blades put on the grinders-  we recommend and sell the lower rpm (higher torque) and higher amp (more powerful) grinders as they perform better and longer for contrators applications.

YES

We consider 7″-9″ Grinders the same.  You can only run up to a 7″ diameter blade with the dust shroud kits

For our Dust avenger 007 and Dust mizer 007 Kits YES you can use a 7″ or 9″ grinder

An Angle grinders inch rating is based upon the amps (power) it has and RPM it turns.  7″ angle grinders will run at a higher RPM (say 8500) than 9″ (say 6500) so the OD blade speed remains at acceptable levels.  9″ grinders typically have higher power rating to compensate for the more energy to turn a bigger blade and also for cutting deeper etc.  when using a 7″ diameter blade/ cupwheel they will have more torque to turn th smaller blade which is good.

Because of the stress a grinding cupwheel and deep/ wide cutting saw blades put on the grinders-  we recommend and sell the lower rpm (higher torque) and higher amp (more powerful) grinders as they perform better and longer for contrators applications.

The Dust Avenger kits have aluminum collars that adapt to each make and model specifically. The Blade nut and arbor adaptor are setup to give the correct offest to use diamond tooling or (Or AVM nuts w/ abrasive disks).  Here are some common issues.

1.  The aluminum collar is the wrong one for your make and model grinder.  The collar  should fit snugly around the bearing housing where the metal blade guard normally resides.  This becomes more of any issue when grinder manufacturers update models and make design changes we havent caught up with.  If the make/ model of your grinder isnt listed on the web, odds are we do not have one for your setup.  we have to choose the most popular makes and cannot make one-off collars.

2. You are using threaded (5/8-11) tooling in which the threaded nut height is too short allowing the blade to be sucked into the shroud too far.  In this case, you should use some 5/8″ ID washers to space out the blade whilst allowing you adequate threads to safely use the machine.  Or use a open arbor (7/8″) blade and use the arbor adaptors provided in the kit to gain the correct offset.  You may also machine down the bottom of the collar to effectively raise the shroud height, at your own cost and discretion of course.

3. The setup we sell you isnt correct.  It happens, we are not perfect.  things change.  if you get it and cant make it work, return it for credit.