Complete ScubaPro MK2/R190/R380 Repair Steps/Parts List...

[ams511]

Support America, buy domestic!
Another possible source is the transparent plastic "box" Samsung used to package their harddisks with, but of course, that's imported too.
Go thru your junk box: the plastic cover for the current SP service kits is about .26mm and should work as well.

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Tried to use a thick plastic box but my cutting skills need work. Will try again with a proper x-acto knife. I just rebuilt a mk-5 and the IP is low also. Before the rebuild it was at 115 IP with 1 shim and a red seat. Now it is at 125 with 1 shim and a + seat. I measured out the shim and I get roughly 1/2 ID and 3/4 OD. I am not sure if my eyesight is off or the shims are metric. These look promising.

 

[Zung]

Way too expensive, keep on digging.
Your measurements are about right; I've got .5"/12.2mm and .787"/20mm.

 

[WolfPackDiver]

Were you able to find the shims you were looking for? The thickness (and hardness) is the important thing for IP. Inside/outside dimensions just need to fit inside the body and allow smooth spring compression without wandering around too much.

 

[ams511]

Were you able to find the shims you were looking for? The thickness (and hardness) is the important thing for IP. Inside/outside dimensions just need to fit inside the body and allow smooth spring compression without wandering around too much.

No I didn't. I decided to go back and read the Harlow book. He mentions that the shims are .012 (I think) but that the wrong material could cause a "cold flow" problem. Unfortunately, he does not go into detail what exactly that means. So I stopped rather than try to experiment. I have a few junker first stages I can strip if I want the shims. I also can convert a Mk-20 to a MK-25 and keep the extra shims.

 

[herman]

Cold flow- the slow extruding of material subjected to pressure without the benefit of heat...or at least that would be my def. I would not worry too much about it, the effect would be a very slow drop in IP, certainly not life threatening. Granted not something you would want to do with a paying customers reg but for your own, I don’t see an issue with it. At worst you have to go back in and replace the shim or just adjust the second stage and go on.

 

[NotSure]

I tried the washers below on a MK5 and they fit a little tight but do work. Someone let me know if they believe these will cause certain death.

PTFE Washer .500 ID x .812 OD x .010 thk 50/pk C13034



[FONT=&quot]http://www.ebay.com/itm/PTFE-Washer-500-ID-x-812-OD-x-010-thk-50-pk-C13034-/390284046419?pt=LH_DefaultDomain_0&hash=item5adebdf053[/FONT]

 

[ams511]

I tried the washers below on a MK5 and they fit a little tight but do work. Someone let me know if they believe these will cause certain death.

PTFE Washer .500 ID x .812 OD x .010 thk 50/pk C13034

[FONT=&amp]http://www.ebay.com/itm/PTFE-Washer-500-ID-x-812-OD-x-010-thk-50-pk-C13034-/390284046419?pt=LH_DefaultDomain_0&hash=item5adebdf053[/FONT]

Well your price is much better than McMaster Carr. When you say it is tight, I assume you mean placing it between the body and the spring?

 

[NotSure]

Well your price is much better than McMaster Carr. When you say it is tight, I assume you mean placing it between the body and the spring?

When I measure the inside diameter of the balance chamber with my cheap calipers I get about the exact same or a few thousandths less than the outside diameter of the shim.

 

[Zung]

I tried the washers below on a MK5 and they fit a little tight but do work. Someone let me know if they believe these will cause certain death...

You're already dead, except you don't know it.
Good find!

 

[herman]

If you need to take a little off the outside of them, put 5-10 or more of them on a bolt with metal washers slightly smaller than the size you want on each side and clamp them tight with a nut then spin them in a drill press or hand drill. I use a lathe but I know most of us don't have one handy. Use a file or sandpaper (100-120 grit is good) to trim down the outside edge as they spin. A file is best. The washers will come out cleanly cut down with no ragged edges, it's faster too. If you can't find a bolt of the proper diameter or it will not fit in your drill, use a smaller bolt and wrap layers of electrical tape around the bolt until the washers snuggly slide on. Metal shims can be cut down the same way but it does take a little longer to do.