DWMistral Seat

[stephen]

Dear Community,

I have taken apart a DW Mistral that I bought on e-bay. I am putting it back together and just want to ask how you know if the seat needs work. This one looks good, although there is a very slight indentation from the metal body seat in the nylon.

I also have two Healthways Divairs (single hose) whch I rebuilt. One of the second stages had a lean valve and the other had the regular type of arm. Maybe I am missing some details that are very important, but it did not seem that hard to me. I just took them apart, cleaned them and reassembled them as they originally were. I found balancing the one with the arm was rather hard - the adjustments needed became very small at the end. Does anyone have any advice? Am I missing something important and potentially dangerous?

Sincerely,
Stephen

[stephen]

Dear Community,
I meant to say Healthways Scubair. Sorry!

Sincerley,
Stephen

[duckbill]

stephen said:

Dear Community,
I have taken apart a DW Mistral that I bought on e-bay. I am putting it back together and just want to ask how you know if the seat needs work. This one looks good, although there is a very slight indentation from the metal body seat in the nylon.
Stephen

If it ain't broke, don't fix it. i.e. if it doesn't leak air, then don't bother with it. A ring indentation is normal. The seat CAN be resurfaced, but if you do this each time you take it apart the seat won't last long. Being that there are no aftermarket seats, make it last as long as possible.
Here is a link for resurfacing instructions.
www.vintagedoublehose.com/downloads/seat_resurface.htm
Note, though, that I have found that seats composed of the white nylon(?) material will sometimes gall no matter what drill speed I have used, and I have found it necessary to finish hand-lap the seat until it was nice and smooth. The drill can do the bulk of the work first, though. Just take it nice and slow, and try to keep the seat as parallel to the sandpaper's surface as possible, especially if hand-lapping. If possible, use magnification to check your progress.

[Captain]

I suspect that if a seat is not leaking just the act of disassembly and reassembly may cause it to leak. I say this because the seat does not rotate when in use it only moves back and forth so the impression in the seat in relation to the volcano orfice is always in the same place. Once the seat is removed and replaced it is highly unlikely it will be in excactly the same position it was in, in relation to the volcano orfice so the impression in the seat no longer matches the volcano orfice. If the position of the seat in the body could be accurately marked before removal and reassembled in the same position I think a lot of leaks and the need to resurface the seat would be unnessary. Just a though I would like to try.