Adhesives: The Final Chapter
Applicators, Tools & Trowels
For the last two issues I have been talking a lot about glues and adhesives. To finish my “glue-run” I want to talk about a few tools.
Notched trowels for mastic and thin-set mortar are very accurate volume measurement tools. Each job has a specification for the notched trowel to use. When the trowel is pushed hard to the surface, and drawn at a 45 degree angle, it will leave a very specific volume of adhesive in rows. When the second surface is pushed into these rows and the adhesive is spread out evenly, you have the exact thickness of adhesive required by the manufacture over the entire surface—like magic. When you try spreading anything with a flat trowel you know how hard it is to get an even application or a well defined thickness. It is important to use the trowel tooth configuration specified by the manufacturer—usually the tile manufacturer makes that call— and it is important to hold the trowel at 45 degrees to the surface. Tip it higher and you get too much, tip it lower and you don’t get enough. One special working tip: always make straight line rows. If you draw tight curves, air gets trapped under the tile and the adhesive doesn’t end up the right thickness. Almost straight lines let the air out one end or the other.
Applying liquid adhesives to large surfaces evenly can be difficult. Notched spatulas don’t work as well as with thick adhesives as with thin-set or mastic that will take the shape, and volume, of the notched trowel. Here is where the bottle fed rollers work so well, either on large surfaces or even board edges. Squeezing the bottle will flow the glue onto the roller and it then gets spread as the roller hits the surface. This can be very important in avoiding bare spots.
Board Centering Applicator
This little attachment goes in the gun before the caulking tube and simply guides the adhesive tip perfectly along the centre of a joist. It stays on true centre at any speed you draw the bead.
Slot applicators are sometimes speciality glue bottles and sometimes just speciality tips to put on regular bottles. The slot applicator has a flat tip with holes on each side for the glue to come out, which permits spreading a very even coat of glue on both sides of narrow slots— like for biscuits, splines or T&G boards. If you were to apply the glue on the biscuit, it would smear all over as it was inserted into the groove or slot. Just pouring glue in with a regular bottle tends to fill the bottom and not spread much on the sides. The Slot Applicator puts the glue exactly and evenly right where it needs to be.
And to cap off all this talk about glues and adhesives, this great little invention takes all the honours of closing off any cut glue tip, be it a small bottle or a large caulking tube. The pyramid shaped plug has a spiral thread cut all around. This allows you to screw it into any sized opening, and the threads keep it there despite pressure from the contents trying to force it out. The plastic is non-adherent for most adhesives, allowing it to be used over and over. For difficult adhesives, like PL Polyurethane, squirt a bit of oil on the plug before inserting and it will unscrew with ease long after other plugs would be stuck solid. It is starting to show up on store shelves but if you can’t find it, check Lee Valley Tools.
Saw and Drill of the Month
Saw and drill in one: Here is the new Lenox Speed Slot Hole Saw. The plug removal design is simple but efficient. Some young lad simply thought of creating a slot with a stair step design allowing three leverage points from which you can force out a plug. There exist fancier and quicker plug removal designs, but none that take no space and don’t increase the cost of the hole saw.
In addition, the Lenox testing is showing that two other innovations in this blade have it cutting many more holes per blade in wood and metal than the competition. First, a narrow kerf design reduces friction. Second, leaving the paint out of the inside of the saw—yes this is the only saw that leaves the paint out— actually reduces friction and heat. What looks like just another hole saw is beating the competition.
Montreal-based TV broadcaster, author, home renovation and tool expert
Jon Eakes provides a tool feature in each edition of Home BUILDER.