Comparing Canister and Bulk Contact Adhesives

It's tricky to make an apples-to-apples comparison between different contact cement formulas in a production environment. March 13, 2009

Question
We are a long time user of Wilsonarts 800 red spray contact adhesive sprayed from our refillable pot. Recently a 3M rep came in to show off his product, particularly the hi-strength 94 glue. He set us up in a "guaranteed trial" - we buy a cylinder and spray gun and if we don't like it he takes it back. He claimed a coverage of about 1300 square feet of counter per cylinder, which would make the $220 per cylinder price less painful.

Well our first cylinder was empty after about 150 square feet. Obviously we were spraying too heavy, and he gave us a second one and gave us a demo. Our second attempt yielded about 325 square feet, about what we get out of a $65 can of 800. I called 3M and discovered it actually should cover 1300 square feet per cylinder or 650 square feet sprayed on two surfaces.

My questions are these:

1. Part of our coverage issues are because it’s very unsettling to spray any thinner than we are now, the appearance is a substantially thinner than we are used to seeing with the 800. If you currently use cylinders (from any manufacturer) are you able to get satisfactory results spraying such a thin coat?

2. Even if we are able to attain the claimed coverage it still would work out to cost roughly twice what I now pay for the 800. Since all of us in business are always working to lower over head, what other unseen cost benefits does this type of system give? Obviously I'm not running my air compressor so there is a slight benefit there, probably not nearly enough to offset the high cost however. Any input would be appreciated. These types of systems seem to be growing in popularity and I would hate to reject a good product without giving it every opportunity to work.

Forum Responses
(Laminate and Solid Surfacing Forum)
From contributor T:
I tried that same system about four years ago, I don't know if it was the same brand. I only used it on one job. I had a vanity top leaning up against a wall (waiting to be installed) over a heat register and it delaminated. My opinion is it's ok to cost more if it is better and faster.

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From contributor D:
We use Wilsonart 950 in pressure pots in the shop, and canisters in the field. The canister adhesive is incredibly aggressive, leaves the air easy to breathe, and it's more portable. We would use it in the shop, except it is too expensive for the volume we use. We have a habit of applying too much of the canister glue, for the same reason as you. Try a single pass without overspray and see how aggressive it is!

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From contributor R:
Contributor D is exactly right in his breakdown of the benefits of the canister. As a manufacturer of both canisters and bulk, both have their place. One tip, if you have a scale capable of measuring grams it would help you would be to measure your coverage with the canister. You can do this by taking a 12" x 12" piece of laminate or substrate, weigh it, spray it, let it flash, weigh it again. This difference will give you your coverage (i.e. 2.5 grams for Wilsonart 700 Canister). The other thing to be aware of is that you really have to watch the coverage advertised by some manufacturers. While most are good, some will not list bonded coverage (i.e. 650 bonded square feet vs. 1300 square feet of coverage) and some will also based their numbers on a lower amount of adhesive per square foot (i.e. 1.0 g/sq ft).

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From contributor A:
Something else to consider when comparing brands of aerosol adhesives is the solids content. An aerosol with a higher solids content will yield more actual adhesive once dried. If you have ever experienced aerosol soaking through a surface, this is an example of a low solids adhesive - most of what you are spraying is the solvent, not the adhesive.

The misconception with spraying adhesives is that more is better, but you can get away with spraying less of a high solids adhesive and still get great adhesion. The coverage data from one product to another (or brand to brand) also may differ, so look at the units of measurement. Coverage is stated for particular amounts of wet adhesive and also for dry adhesive.