Air Gun Home :: View topic - Anyone familiar with Macarri's glue on piston buttons?

333mmm · New Member

Has anyone used Maccari’s glue on piston buttons? Are they effective? How difficult are they to install? It seems that if they’re not sanded down very evenly that the piston would ride along the tube sloppily. What is the best way to sand them evenly? With the piston chucked to a hand drill and sanded with sandpaper held in the hand? I guess they’re very durable because Maccari says on his site that he checked the buttons after twenty thousand shots and they were still in good condition.

Slavia · Moderator

I looked into those buttons for my Mendoza project:
http://www.airgunhome.com/agforum/viewtopic.php?t=2396&start=15

I experimented super glueing soda bottle material to steel, and no matter how I tried it separated (always from the steel - the glue stuck to the plastic). Cleaner/degreaser, Oops!, brake cleaner, Dawn dish liquid, muriatic acid - no luck. So I went to the local welding shop and had a glob of brazing rod globbed on all the way around.

I worked that down by hand with a file, measuring frequently with a dial caliper. I turn a lot of things with a drill, but never that long or that wide - they just wobble and one side gets ground down at the expense of the others. I would have spun it had a lathe been available, but not with a drill.

Should you opt for the buttons, I would certainly follow Maccari's instructions. I would be compulsive about degreasing the piston. I would buy fresh, new super glue of a name brand - not the generic dollar store stuff. To size the buttons, I would get manicure emery boards:
http://www.airgunhome.com/agforum/viewtopic.php?t=2875
Take one stroke per button, and try it for fit. One more stroke per button, and try it - and so forth.

While you're in there remember to de-burr all the sharp edges with a Dremel or diamond file. Polish the spring ends with 600 grit or finer abrasive cloth. Think about thrust washers.

333mmm · New Member

Slavia · Moderator

kanyon · Silver Status Member

If yer can....Tig or braze 3 blobs of bronze on the piston and remachine them to a close fit.

TerrySpringer · New Member

i have used these.
when i glued them on the piston everything seemed fine. they were rock solid after they dried up, but as i was sliding the piston back in the comp tube one of the buttons got caught up on the edge of the comp tube and popped right off.
i installed it anyway to see if i could notice any difference. so i fired a about 100 shots or so and i didn't notice any difference in the fire cycle. only noticeable difference was a 30 fps drop in velocity..
so off they came..