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Post by nikeajax on Aug 1, 2015 19:47:45 GMT -8
Just for grins I decided to try to see if I could resurface the valve seat in one of my Conshelfs; well it worked!
Method: wrap masking tape around shaft of seat. Next, GENTLY lock it down in a drill chuck. Lock drill down in vice with drill pointing upward. Turn on drill. With a bit of wet 600-grit paper, hold sand paper over spinning seat. Rinse and repeat until surface mars are gone or mostly gone. Repeat same process with 1500-grit wet-dry paper. Finally, use toothpaste on end of cloth in same fashion. Rinse thoroughly making sure toothpaste is gone from inside of valve seat shaft.
I just installed this in my MR-12, locks up tight, ZERO leakage! Now I have to get a longer actuator pin...
Jaybird
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Post by SeaRat on Aug 1, 2015 20:04:39 GMT -8
I may have to do this with my Hydro Twin, which has developed a small second stage leak.
John
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Post by herman on Aug 2, 2015 4:13:12 GMT -8
Another method is to tape to sand paper down to a flat surface. A pane of glass works but I prefer a 12x12 ceramic tile...you can usually pick up an odd one in the discount section of home improvement stores, just be sure to get one that is slick. I prefer wet/dry auto body type sand paper, it's a higher quality than wood working stuff, it is easy to find in any auto supply. I start with 600 or 800 grit and finish with 1500-2000 grit,keep the sand paper wet with water, it works much better wet. A high power magnifying lens is good to have to inspect your progress, I use jewelers loop for this. The part to be lapped (term for what we are doing) is to move the part in a pattern that does not move the part in one direction, back and forth or side to side is a BIG NO NO. I prefer a figure "8" or infinity pattern. Use light steady pressure and rotate it in your fingers often. This prevents lapping the part uneven, a common mistake and very bad on the sealing of the part.
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Post by nikeajax on Aug 2, 2015 10:10:48 GMT -8
I have a tremor in my hands, so I find that the drill-method is really forgiving, and super fast to boot: it only took me about two minutes!
BTW, what material do they use for the seats? On the MR-12 I noticed that there are four lateral holes in the side areas filled with said material to keep it from walking/secure, and as I remember USD has one, can't remember about Dacor... The Voit was black, whereas the USD and Dacor are brown stuff: the Voit was super brittle and started getting blown to oblivion when I tried to polish that seat and tested it!
Jaybird
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Post by SeaRat on Aug 2, 2015 15:35:05 GMT -8
I haven't done this in a few years for first stage seats. Are your descriptions above for the first stage or second stage?
When I did it, it was for the Mistral seat, and I resurfaced these seats using my knife sharpening stones. I started out with a whetstone that had both a rough and a smooth side, on the rough side. When I got it where I wanted it, I switched to the smooth side. When that was completed, I finished it (polished it) on a marble stone.
John
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Post by nikeajax on Aug 2, 2015 15:52:11 GMT -8
John, sorry, I should have said, "first stage"...
For second stages, I have found using the blunt end of drill bit the same size as the bore can really help if you have a nick in it; just push it through a few times until it goes through easily...
Jaybird
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Post by duckbill on Aug 3, 2015 21:39:56 GMT -8
Thanks for the tutorial.
There were some very early regulators, and I believe they were Voit, that used a hard wax type seal. It may have been poured into the seat and allowed to harden. Very brittle and crumbly.
Some seat materials don't take kindly to the drill method as they tend to gall, making lots of tiny indentations. If the drill method works, then it is easier, but I now hand lap all my seats using very fine sand paper on a piece of glass. You didn't mention what rpm your drill was running.
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Post by nikeajax on Aug 4, 2015 8:56:16 GMT -8
DB, not really sure, but pro'lly about 350-400 RPM... I'm quite fortunate, as my LDS owner really likes me and will sell me any parts he can get, so it wasn't like I couldn't get another one, I just wanted to see if it could be done!
Jaybird
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