Industrial strength velcro peeling off MDF

adhesivemdf

I bought some industrial strength low profile velcro in order to make wall mounting stations for a fan. The fan (about 8 lbs) slides onto hooks screwed into 24"x7" pieces of 1/2 inch thick MDF. The loop side of the velcro is stuck to the back of the MDF in two ~23 inch strips at the top and bottom, and the hook side is stuck to the wall.

I put these up in two places and let the adhesive sit for 24 hours before using them. On one, the MDF-adhesive bond started failing after about 12 hours of holding the fan, and on the other, the MDF-adhesive bond started failing after about of week of holding the fan intermittently.

How can I prevent the adhesive from peeling off the MDF? Would super glue stick better?

Best Answer

Super glue might work, although my first thought was to finish the mdf with polyurethane first. This will seal the mdf and allow the adhesive to remain sticky for a long time. Rubbing superglue on the area before the velcro goes on might get the same result too if you don't want to finish the whole thing.

I think this is what's going on : the mdf is very porous and absorbent. For example, it soaks up finish rapidly until it's saturated and only then can you build up finish thickness. I think the mdf is basically extracting the lower molecular weight components out of the velcro adhesive, which are the that make it tacky. With those gone, the adhesive is now more brittle and fails in short order.