Applying tape edges to plywood

[l-lopez]

I am attempting to finish the edges of some plywood with birch strips coated with heat sensitive glue. I used an old steam iron at maximum temperature (linen) and without steam, and moved the iron slowly along the board - forward and then backward. I then used a "J" roller to apply some pressure.

For the most part, it worked well. However, I am finding spots where the glue did not take - or it released after I put the board away. Is there something wrong with my technique? It the proper repair - just re-heat the area, or should I force some wood glue into the spots and apply clamp pressure?

Thanks, Len

[Robatoy]

The J-roller does not cool the heated tape enough to allow the adhesive to 'set'. After the J-roller leaves, the tape just lifts again. The best 'heat-sink' to use is a chunk of flat metal. It presses the tape in place, and removes the heat. Since I no longer own an edge-bander, I now use a 2" wide strip of Corian, about 4-6" long and use it as a 'cold iron'. A piece of granite or another smooth stone works well too.

If you're planning on doing a lot of this, try to find an old iron without the holes. Plug it in, let it heat up, and unplug. Wait a couple of minutes and spray with Top-Coat. As the iron cools, the TopCoat gets trapped in the porosity of the iron's shoe and will stay slippery for a long time.

[whit3rd]

The joint has to stay in contact while it cools, but has to get hot enough to force glue into the open-grain edge. You can reduce the heat somewhat by priming the edge with glue (I paint-roller with PVA white glue and give it a day to dry), or you can hold the tape in place by sliding a block after the iron has passed. In mass production, the hot band goes on, then the edge presses against an outfeed fence.

The J-roller is fine for contact cement banding. Back/forth ironing seems unproductive (it only takes ONE heat to do the job).

[l-lopez]

Thanks for the tips. I found that following the iron with the heavy edge of my 12" machinist square on the tape drew enough heat away to get the glue to set.

Len

[RicodJour]

You should also experiment with the heat setting. You're looking for that sweet spot between the heat setting and the speed with which you feel comfortable moving the iron.

R

[Upscale]

If you're having trouble with the iron on type of edge banding, you could try the straight veneer wood type that you apply your own white carpenter's glue. I've used both and while the iron on type is convenient to use, the apply your own glue type holds better in my opinion. The options with it are to use finger pressure for about a minute in any spot, use edging clamps or perhaps a strip of wood clamped against the veneer.