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Build a Pressure Tester for 30 Dollars

mucrewbtp

Horology Curious
18/12/06
6
5
0
DISCLAIMER: I am posting this procedure as an explanation of how I created my own tester. This device operates under high pressures and can be dangerous if manufactured or used improperly. Always wear eye protection while using any pressurized device. I am in no way responsible for any damage or injury that may result from the construction or use of any device not created by myself.


Ok, now that that is over with on to the tutorial, sorry for the crappy pictures.



The shopping list:

One wide mouth Nalgene bottle: $15 in college bookstore, $9 here: http://www.nalgene-outdoor.com/store/detail.aspx?ID=53
IMG_0685.jpg


Be sure you get an actual Nalgene brand, Made in the USA bottle. These are made out of a shatter proof polycarbonate that will withstand the required pressure. It also has a lid design that does not require any additional seals.

One bicycle inner tube: $3.95
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Cut a three inch circle out of the inner tube with the valve directly in the center. After trimming the valve wash the rubber thoroughly. As it comes the rubber has a coating on it that will keep the adhesive from sticking.

One foot operated bicycle pump with gauge: $10
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Be sure that the pump has the type of filler attachment that locks on to the valve stem. An integrated gauge is also very helpful.


The Procedure:

1.) Drill a 5/16" hole through the center of the lid. The lid already has a dimple in the top center which makes it very easy to properly locate the hole.
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2.) Using a silicone adhesive sealant (Not my favorite but it seals well and dries fairly quickly) glue the valve to the inside of the lid. The rubber circle has to stay inside the ring that sticks out from the lid to seal it to the canister. Its hard to see on the picture but is obvious when you have the lid. As a helpful tip, i used the top of an aerosol can to apply even pressure to the rubber valve while the adhesive was drying. If you can't find one the right size, the top to a small can of RemOil gun lubricant is the perfect size to fit within the lip on the lid and hold the valve in place.
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The finished lid should look like this when it is done curing.
IMG_0695.jpg



Now for the testing procedure:

1.) Fill the bottle with about 400 CC of water.
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2.) Select your test subject, in this case an MBW DRSD
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3.) Attach a length of scotch tape through one of the spring bars, this is how you will hang the watch in the canister.
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4.) Tape the watch so it hangs in about the middle of the canister, above the level of the water. Tape the watch to the mouth of the canister, this way it will be easier to retrieve. Keep the tape slightly below the very top of the mouth because the lid seals to the inside top surface.
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5.) Next tightly close the lid on the canister, then attach the pump to the valve stem. Hold the stem while you put the pump on. Too much downward pressure can cause the valve to come loose.
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6.) Pump up the canister while listening for leaks. As the pressure increases the lid will become slightly domed. As this slightly changes the shape of the sealing surface, it is necessary to tweak the lid tighter a few times while increasing the pressure. A very minor tightening will quickly re-seal the lid. I pressurized this test to 85 PSI, which is about 5.8 ATM.
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7.) Allow the watch to sit pressurized for a few minutes in order for it to equalize, if it is going to. Keep an eye on the pressure, it may need a pump or two to maintain pressure depending on how well everything is sealed up. In this test, the canister held 85 PSI for five minutes while i left to run an errand.

8.) After waiting, remove the pump connector from the valve. Then use the end of a ballpoint pen, the kind with a retractable tip, with tip retracted to slowly release pressure. While releasing pressure tip the canister on its side so the watch is submerged. Continue to slowly release the pressure in the canister. The idea is to watch for a steady stream of bubbles that would indicate a leak.
IMG_0709.jpg


In this picture I had a small bubble come from under the bezel, keep in mind that almost six times as much air that is normally under the bezel is now inside that space. As this air expands it will show up as bubbles, this does not indicate a leak. A leak will be an obvious steady stream, imagine 5 times the air volume of the inside of the watch case escaping. If you have a leak, you will know it.

9.) As the air in the canister is almost released tip the canister back up while still de-pressurizing until no pressure remains. Do not release all of the pressure with the watch still submerged, if you have a leak, this will allow water in.

Thats all there is to it, this watch passed as you can see by the picture of the test. The watch has been upgraded with a Clark superdome, and all seals have been checked and greased. A gen crown and tube are in the works as soon as I can locate the proper tap for the case hole. As a side note, if anyone has a tap to lend, I would greatly appreciate it.

If anyone has any questions about the construction, or testing procedure feel free to PM me.

I hope this has been helpful,
-Mike
 

watchbuff

I'm Pretty Popular
13/2/07
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That's awesome
I just changed a bike tube and have a spare sports bottle like that and a good yand pump. I think I'll try it/
 

Dizzy

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thats so cool!!!

i dont have any of the parts... but after a quick trip to Wallmart...
 
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lumpyone

Active Member
7/1/07
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nice...ive been thinking of how i was going to build one....this idea is much simplier that the one i had in mind....thus...better.
thanx
s
 

SD4K

Renowned Member
25/10/06
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Thank you for this cool tutorial!
AWESOME!

Someone sticky it. :D
 

takashi

Legendary Member
4/4/06
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A very interesting and worthy things to do.

I am stickying this.
 

rbj69

I'm Pretty Popular
14/3/06
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this is very cool , if i didnt already have the burgeon pressure tester i would have made me one of these(i dont know how accurate the pound per pressure would really be from a bicycle pump but i bet is it good enough to give u peace of mind)

nice tutorial

joe(rbj69)
 

fakemaster

Mythical Poster
31/5/07
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I shall try this. If you don't hear back it means I died in the explosion :p
 

vejaman

You're Saying I Can Sell?
1/11/06
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very nice. Additionally, you can go to AutoZone, Checker or any other auto parts store and buy valve stems that are designed to fit into the hole you drill and eliminate the need for glue.
 

avitt

Active Member
23/4/06
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vejaman said:
very nice. Additionally, you can go to AutoZone, Checker or any other auto parts store and buy valve stems that are designed to fit into the hole you drill and eliminate the need for glue.

Yup, just like this:

img3068nf2.jpg

img3073hv6.jpg

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guillaumelou

Known Member
27/2/09
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Very good idea this tester. I will do it.

But I disagree for the technic explication. When you put the watch in the bottle and close the bottle the pressure inside the watch and inside the bottle are the same. When you pump the pressure inside the bottle goes up. For the watch there are 2 way : it's water resistant at this pressure and the pressure doesn't increase inside the watch, so when you let the pressure go down after several minutes, when you put the watch into the water theris no bubble that mean no leack and good watre resistance at this pressure, but second way, if the watch isn't water resistant at this pressure, the pressure increase inside the watch in order to equilbrate, so the pressure inside the bottel and inside the watch become equal after several minutes, so when you let the pression decrease inside the bottel in order to restablish normal pressure, the pressure inside the watch is always high and so higher than in the bottle, so when you put the watch into the water the air escape in order to equal the pressure and so you see bubbles and the watch isn't water resistant at the pressure used for the test.
 

levelmanroger

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1/10/08
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What's the risk of water getting into the watch under this testing method (if the watch fails). Logic tells me that if the watch is under water only when releasing pressure, then water could not enter. Fear tells me that I'd ruin a watch!
My watch smith charges @ $50 for this test, but he removes the movement to do the test - just in case of catastrophic failure.
 

JellyJoe

Put Some Respect On My Name
28/9/09
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As most works of geniuses, this invention is simple and yet very smart. Nice post and very well explained tutorial mate.
 

wilson

You're Saying I Can Sell?
26/10/09
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I'll be willing to bet that I will end up with some sort of injury, but Im going to try anyway! Thanks!!
 

Bradafc

Horology Curious
17/3/10
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Anyone willing to make me one and ship it over to uk willing to pay more for the inconvenice(sp?)

also I would only really wear my watches swimming in pool Or shower. so won't go no deeper than say 10m what ATM would that be???
*
 

Francisco

Active Member
23/12/07
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Anyone willing to make me one and ship it over to uk willing to pay more for the inconvenice(sp?)

also I would only really wear my watches swimming in pool Or shower. so won't go no deeper than say 10m what ATM would that be???
*

2.5 or 3 ATM is enough...