Sealing Pouches, using Dow Corning 3140 RTV
A Word of Caution: You want to use Dow-Corning 3140 RTV, which is a very thin based RTV, intended for use in the Electronic Industry, Potting (Covering, Sealing) delicate Electronic Components.
YOU DO NOT WANT TO THIN THE DOW-CORNING 3140 RTV. IF YOU THIN THE RTV, IT WILL SOAK INTO THE LEATHER, WHICH LEAVES YOU WITH A STIFFER POUCH
The Dow-Corning 3140 RTV is available at Ellsworth Adhesives. Their web address is
http://www.ellsworth.com/display/productdetail.html?productid=225&Tab=Products
Current Website Price is $23.64 for a 90ml or 3 ounce tube. They do have a 48 dollar minimum order
Another Plus for using Dow-Corning 3140 RTV is the UV
additive, allowing you to view coverage with a Black Light!
Stopped coating for a phone call? Where did I stop? Pull out the UV and see for yourself.
If the cost seems to be high, one three ounce tube will seal a complete set of pouches, AND seal the leather I use to cover ALL small and medium pneumatics! Compared to the overall cost of the job, is not much!
I have used only Leather for covering ALL small and medium pneumatics, meaning pneumatics, tracking, governor, wind motor, sustain and any other in this class, for some years now, with great results.
I purchase my Leather from Columbia Organ Leather, at http://www.columbiaorgan.com/col/
OR
The Leather Supply House, at http://www.leathersupplyhouse.com
Step One of Four
Dow Corning 3140 RTV applied to seal pouch - Don't over do it!
StepTwo of Four
RTV spread over pouch leather using fingertip
Step Three of Four
Using tissue to remove excess RTV. Hold pouch in one hand and use tissue in a
circular motion, folding tissue between wipes, and changing tissue for each pouch!
I also find that terry cloth works well. Just keep moving the area used for wiping off the RTV
Step Four of Four
Wipe the pouch using a circular motion until all
shine is gone, then turn tissue to unused area and repeat.
I hold the pouch board in my Left hand, and the tissue in the right. Sorry,
but my right hand was holding the camera in this picture. ALL excess RTV MUST be
removed. You do not want a shine when examined at an angle
Nipple has been installed at this point, and with all openings sealed, and the nipple connected to a
bubble jar, you make sure that all is tight at this stage. I test using eight inches of water feeding
the bubble jar. This is my personal preference.
Bubble jar with open input. Look at the size of the bubbles (actually you cannot see the individual
bubbles, but this picture stops the action) and the froth at the top. Lots of bubbles!
Bubble Jar attached to the nipple of the pouch. See the one small bubble rising to the top. The
bubble jar is testing the tightness of not only the pouch, but the pouch block as well.
I want to THANK Craig Brougher for introducing me to the "Bubble Jar" I found that it has caused me more work, but get better results!! Sure saves time in the long run!
Thanks Craig!!
For more information, Contact Al Pebworth at the link below
al@pebworths.com
Page Last Updated 1/15/2009
