MM-80
TYPICAL QUESTIONS

............Q1 SHOULD WE USE MM-80 IN REFRIGERATED AREAS?

A. MM-80 can be used in all areas where the ambient temperature will be maintained at 32 degrees F or higher. For all areas below 32 degrees F we recommend the use of our Spal-Pro RSF, which was developed specifically for such use. 

Q2 WHEN SHOULD MM-80 BE USED? WHEN IS EDGE-PRO XL ACCEPTABLE?

.........A. There are three basic factors to consider:

¥ the ACI floor classification
¥ the wheels on the material handling vehicles
¥ the anticipated loaded vehicle weight

In brief, Class 6-9 floors, small hard wheels, and heavy loads require MM-80's "heavy duty" reliability. Class 5 floors (moderate duty) with larger, softer wheel traffic and lighter loads may permit the use of our "XL." For specific recommendations call Metzger/McGuire or refer to our Joint Filler Selection Guide.

Q3 PLEASE EXPLAIN WHAT YOU MEAN BY "SHORE HARDNESS OF A-80?"

A. Shore hardness is a reading taken by a measuring gauge called a "durometer" which has a scale of 0 to 100. Shore "A" represents the relative hardness of rubber, soft plastic and semi-hard materials. Shore "D" measures the relative hardness of plastics and other hard and semi-hard materials. As a reference point, MM-80's Shore "A" of 80 is roughly comparable to the rubber of a truck tire.

Q4 WHY MUST MM-80, OR ANY OTHER JOINT FILLER, BE INSTALLED FULL DEPTH?

A. Epoxies are typically weak when in shear. If they do not have a solid base to rest upon (the bottom of the saw cut), they can be driven down by point loads, leaving joint edges exposed. Refer to sheet T2, "The Concept of MM-80," and our article "Cheating on Industrial Floor Joint Filling."

Q5 WILL MM-80 FLOW INTO A NARROW SAW CUT MADE BY A SOFF-CUT SAW?

A. Yes. MM-80's viscosity is calibrated to flow into a 1/8" wide cut, which is the width of most Soff-Cuts after a few weeks.

Q6 SHOULD WE USE MM-80 IN COLUMN DIAMONDS AND JOINTS AT WALLS?

A. The general rule of thumb is that MM-80 should be used in joints that could be exposed to hard wheel traffic. Some column diamonds may have this exposure. Joints at walls don't.

In non-traffic joints a polyurethane will be less expensive and actually perform better.

Q7 MM-80's ELONGATION IS 24%. DOES THIS MEAN IT WILL TAKE 24% EXPANSION?

A. An emphatic No. Elongation is a measure of how much a filler will stretch "lengthwise." Floor joints expand laterally, side-to-side. Most concrete shrinks at a rate of 1/16" to 1/8" in 20'. This means an expansion of 50% to 100%. MM-80's expansion capability is approx. 5%. Even the most flexible semi-rigid epoxy can tolerate only about 10% expansion before adhesive or cohesive separation takes place.

Elongation is a much misunderstood and abused term in our industry. Don't be mislead by high elongation properties.

Q8 SHOULD MM-80 BE USED IN SHAKE-HARDENED FLOORS?

A. Yes, in fact it should be used since the use of a shake-on hardener tells you the floor is expected to be subject to severe, heavy duty traffic. MM-80 is the only true "heavy duty" joint filler.

Q9 SHOULD MM-80 BE USED IN SHRINKAGE-COMPENSATING FLOORS?

A. Yes, but it must be recognized that the wide joint spacing common to shrinkage-compensating floors may result in more opening at each joint. Accordingly, deferring the filling as long as possible is very important.

Q10 CAN MM-80 BE PROVIDED IN COLORS OTHER THAN GRAY?

A. Yes, MM-80 can be color matched to almost any color (translucent not available). It can also be field-colored by adding mason's color to the "A" part prior to blending with the "B" part. Request sheet T30 for additional information or call Metzger/McGuire.

Q11 SHOULD MM-80 BE USED TO FILL JOINTS THAT WILL BE
........COVERED WITH TILE?

A. Joints under tile generally do not require the same degree of protection as exposed joints. Thus, we normally recommend that tile covered joints be filled with our moderate duty filler, EDGE-PRO XL. See technical sheet T-4 for complete information.