I need a sealant that will cure underwater.

[GK]

I am a consultant and I am providing engineering / material science services for my client who is in need of sealing a water leak in a forestry piping system.  The system pumps clean and filtered water from a lake.  In an unpressurized section of PVC pipe (outside / exterior location), a leak has developed.  I can either remove the pipe sections, break apart the concrete footings and supports, then re-install a new section of pipe and valves - VERY EXPENSIVE !!! Or, I can inject a sealant into the pipe from an opening above, which would (hopefully) seal the water leak for good.  <br><br>I am looking for a sealant (or adhesive) which I can inject down into the pipe section (about 6 inches down) which would cure underwater to positively seal the low pressure water leak.  The water temp. in the summer is around 70 deg. F.  The water temp. in the winter is above 40 deg. F.  I'm trying to figure out the best method of injecting this sealant.  My first impulse is to pour the sealant into a metal cylinder (like a grease gun), then inject the sealant (using an air compressor) to force the sealant to it's desired location.      <br><br>QUESTION:  WHAT TYPE OF SEALANT CAN I USE ???  WHAT TYPES OF SEALANTS WOULD CURE UNDERWATER ?  WHERE WOULD I PURCHASE THIS SEALANT ?  DO YOU KNOW OF ANY COMPANIES THAT CAN HELP ME OUT ? <br><br>Thank you<br>George Kremer - Jet Edge Consultants

 

[kevS]

Silicone should seal just fine underwater. Try GE. They make the stuff in all sorts of viscosities. How about using a silicone rubber patch with silicone sealant applied to it. Hold it in place with hose clamps.

 

[loeb]

I know of two sealants used on boats that will cure under water.

There are epoxies that will cure under water, but in order to get them to stick to PVC, you need to first apply some PCV solvent. Even then, I'm not sure that you'll get the best bond. You can contact the Gougeon Brothers, the makers of West Systems Epoxies. They are very helpful and knowledgible.

3M also makes sealants for boats and of course are VERY knowledgible. I can't remember if it's Polysulphide or Polyurephane (probably polysulphide) that NEEDS water to cure. I believe that the product names are 4200 and 5200. A 3M representitive can probably help you.

 

GK - Try looking through the following web site, which I found helpful for a similar enquiry -

http://www.chem-crete.com

 

[WKTaylor]

GK...

A few words of caution..

I have been sealing fuel leaks on acft for Years... and never had much success when the problem is poorly-defined...

It sounds like You have not defined the mnature of Your pipe leak: is it a break, a crack, a hole, a loose fitting... etc?? If You don't know is that OK???

If injecting sealant under pressure, be very cautious: excess sealant could enter and plug the pipe You are trying to fix... especially if it is not sticking to the pipe. Pressure injection has to be controled.... other-wise the sealant could go any/every-where! At best, I sense that You may end-up with a temp repair.

Is pipe imbedded in the Concrete footing? If not, perhaps it could be extracted and replaced without damaging the footing. If it is, Does it HAVE to go under/thru the concret footing? If NOT, perhaps plugging the old system and then routing new plumbing around the footing [in an more accessible &quot;way&quot;] would be a wiser &quot;fix&quot;.

Regards, Wil Taylor

 

Try the ShinEtsu silicone KE-3475-T. A customer of mine uses this product to seal a plastic filament underwater. They inject with a syringe - needle.

 

[bookie]

Try using polyurephane. You can purchase it at The Home Depot and I'm sure any other department store. The price for it at Home Depot starts at .25 up to 25.00 for a gallon.
I hope you've found this information helpful.


Miranda

 

[Glueguy]

My suggestion is a moisture cure urethane. The bonding structure of the higher grades are available for sealing below the water line. Since urethanes have such a wide bonding range, I would use it on a boat or a conrete basement. It costs approx. $10 - $12 for a standard caulk tube and is sandable & paintable (which most silicone is not).


I hope that I've helped,
John

 

[jcraig]

Polyurethane grout products are used to stop leaks and I have tested these on seawalls, pumping them underwater to seal joints and gushing leaks as well.

For fast set, we have our Prime Flex 920 which is a Hydrophobic rigid foam material. We also have a slower set, yet very successful sealant Prime Flex 900 which is a Hydrophilic flexible foam sealant used for pipes and joints.

More information and case studies (including an aquarium project can be found at our website:

http://www.primeresins.com

Julie Craig-Merced
Corporate Technical Services Engineer
Prime Resins, Inc.
2381 Rockaway Industrial Blvd.
Conyers, GA 30012
Phone: (770) 388-0626
Fax: (770) 388-0936

http://www.primeresins.com

 

[Walyo]

Like Wil, I also think you may not have thought this problem through. I don't get the picture of what you want to do. Are you proposing drilling a hole in the pipe on the side opposite the leak and injecting the sealant from the hole side? Are you looking for a thick sealant material to bridge over the leak? Can't you access the leak from the outside and seal it with a sealant and a plate?

In answer to your simplest question, I'd recommend a polysulfide type sealant. PRC-Desoto International markets several of these, and their 2701, I am told can cure underwater.

Best regards
Tom

 

[samv]

I'd like to hear your opinions on the life expectancy of the following types of sealants/glues.

Silicone
Urethane
Epoxy

Feel free to discuss other types also...

The application is not exposed to sun - but is exposed to water, ice and hot and cold outdoor air.

 

[8005218874]

I think you might try one part RTV silicone rubber which has adhesive properties and is moisture curable. Adjust stiffness by adding fillers to it so that it could withstand water pressure. United Chemical Technologies have a variety of RTV/sealant systems available

Godd luck!

Alex Shaikevitch, Performance Friction Co.