Question: When you were installing your Treadmaster, did you grind back to clean metal and glue it down, or did you, as I was advised, paint with epoxy first?
Answer: Our boat was already covered in epoxy putty, which still had a good bond, so we glued to that with West System epoxy. If I were putting Treadmaster on bare aluminum, I would use the West System two part aluminum etch (we have had great luck getting a good bond after treating bare aluminum with this stuff) and then glue it down with West System epoxy slightly thickened with colloidal silicate. Note that we have friends that did not acid etch the aluminum and the Treadmaster peeled off on them despite aggressive wire brushing and cleaning prior to putting it down.
Hi John,
The tip with etch is interesting because all the paint shops we talked to put the primer directly on the freshly ground aluminium, which is also the Akzo Nobel recommendation. I still think the etch is a good idea, but perhaps not necessary on a new hull.
The drawback of installing the TM with etch and epoxy in a bombproof way is removing it when it needs replacement. So I was wondering whether etch, an epoxy coat and then an adhesive that is easier to remove would be an option. Perhaps something that softens when heated to let’s say 80 degrees (Celsius that is) with a heatgun. (Similar to some of the Locktite variants).
Thanks
G
Hi George,
The paint shops don’t want to use an etch because it’s difficult to use and highly toxic, but it’s also the best way to get paint, or anything else, to stick to aluminium.
There are also etch primers that include the etch in the primer. Not quite as good, but workable as long as the instructions are followed to the letter.
As to other glues with Treadmaster, from what I have seen most fail quite quickly. We had no adhesion failures when we sold the boat, after 17 years.