neoprene washers

[cessna]

I am attempting to expand type L 5/8 OD tubing for fire tubes in my boiler, I made an expander as per the plan, I purchased what was supposed to be neoprene washers, they looked like ordinary black tap washers and pretty much disintegrated when I tightened up on them, the tube did expand some but leaked at both ends under pressure, my question is where do I find these washers, where are they used?
Thanks
Terry

 

[GailInNM]

Terry,
McMaster Carr has a good variety.
http://www.mcmaster.com/#neoprene-rubber-washers/=d4gr3t

OR

you can get neoprene sheet from most any seal/gasket supply and cut your own. Many auto supply stores also carry it. They are a pain to cut, but it can be done by using a sharpened piece of tubing to cut the inside hole in a drill press at low speed. A drop of oil helps. Then cut the outside with a sharp knife with the rubber between two metal washers with a bolt holding the sandwich together.

If your time is wor anything and you can get a suitable size it is cheaper to buy them.

Gail in NM

 

[cessna]

Thanks Gail.