Model # 300142

Internet #100203505

Store SKU #402470

Store SO SKU #125490

Oatey 8 oz. No. 5 Lead-Free Paste Flux


8 oz. No. 5 Lead-Free Paste Flux

$464 /each
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Product Overview

This Oatey 8 oz. No. 5 Lead-Free Paste Flux is a smooth, non-runny paste that applies easily and spreads evenly. Paste flux cleans and fluxes copper piping to provide uniform solder flow. The self-cleaning formula is good for soft solder applications of copper tube and fittings in plumbing, HVAC, fire sprinkler and other systems. This material is safe for potable water applications.

  • Effective on most metals, excluding aluminum and stainless steel
  • Compatible with common plumbing solder alloys
  • Good for large diameter copper piping
  • Formula resists turning copper piping green
  • 100% lead-free flux cleans and fluxes copper piping
  • Petrolatum base provides effective cleaning
  • NSF standard 14 (performance) and standard 61 (health effects) certified
  • Safe for use in potable water applications

Info & Guides

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Product Depth (in.)
Product Height (in.)
Product Width (in.)


Maintenance, Repair & Supplies Product Type
Miscellaneous Repair Kit

Warranty / Certifications

Manufacturer Warranty
1 year

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Customer Questions & Answers

Why would I use number 5 verses say 95?

What is the best one for home plumbing?
Asked by: Vern
I've always used No. 95 and never had an issue. I used No. 5 a few days ago and had hours of headache, never being able to create a clean joint. Soldering didn't work at all. I'd stay away fro No. 5. I'm not a plumber, but I have almost 20 years experience sweating joints as a homeowner.
Answered by: WeekendWarrior
Date published: 2017-07-06

can I use it for the tube who has pierced?

Asked by: aa
Please be more specific on your question. I don't understand what you are asking.
Answered by: Oatey
Date published: 2017-05-30
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Customer Reviews

8 oz. No. 5 Lead-Free Paste Flux is rated 2.9 out of 5 by 7.
Rated 1 out of 5 by from Maybe I received a defective batch? To give some background, I've been a home owner for almost tw... Maybe I received a defective batch? To give some background, I've been a home owner for almost twenty years. I've sweated many a joint. I've moved my well holding tank from my garage to my basement, requiring probably over a dozen joints. I've built a solar heating system from scratch, requiring dozens of joints. I've run hot and cold water to new sinks. I've done a lot of sweating. I've *always* used Oatley No. 95. About two weeks ago, my well holding tank died and I had to replace it. Translation, no water for the entire house once I decide to take out the defective tank and replace it. To my surprise, I wasn't even able to push the joints together once I put the flux on (even though I was able to dry fit them). I filed one connection down to the point where I could see copper all over my pants. I finally was able to force the joint together. However, even with map gas, I couldn't get the flux to flow well into the joint. I didn't even try continuing, because I knew something was wrong. I finally decided to look at the reviews and I see that others have had my problems. I went back to the home depot the next day (remember, we still have no water) and picked up the old oatley paste that I always use and things were back to normal. Joints slid right in, the joints sweated when I put heat on them like always and I didn't have a single leak. I'm not a plumber, so take my advice with a grain of salt. But again, I've sweated joints *many* times. This flux simply didn't give me any of the results I've seen in the past. Either I got a bad batch (as some people seemed to have no problems with this) or this product is actually supposed to be used for something else and Oatley simply is mislabeling this product. Either way, I'd say stay away and use Oatley No. 95. I literally spent four hours trying to make connections that normally would have taken me 30 minutes, and that was just on the first set of joints!
Date published: 2017-07-06
Rated 5 out of 5 by from Class Listen Up Great Product Used to solder SA602 double balance mixer SMT 8 pin ice clean board with rubbing alcohol,applied paste ,still did not believe then lightly touch hot soldering iron to pin of ice and Wawa la. Please don't beloved fake reviews product works extremely well.Class Over
Date published: 2017-02-25
Rated 5 out of 5 by from Works Great I'm a Master Plumber and have used this for years. I've dabbled with other brands and always come back to Oatey No5. La-Co is too thin and gets on everything. Water soluble just burns and creates leaks. This flux is the best there is, don't let the other reviews mislead you.
Date published: 2015-05-30
Rated 1 out of 5 by from Use the regular flux, not this paste It just doesn't work as well as the "conventional flux". It performs not well and I had to redo the connections I used this stuff for. Not good!
Date published: 2009-09-01
Rated 3 out of 5 by from wrong description as most of the paste and flux on this one also has the wrong description. Home Depot doesn't know the difference between solder paste and flux.
Date published: 2015-11-07
Rated 1 out of 5 by from This is junk It doesn't flow as well into the joint as the "old fashioned" stuff - result: leaks. Had to redo all my joints. JUNK!
Date published: 2014-09-15
Rated 4 out of 5 by from Paste Flux Soldering pipe for plumbing work. Seems to have more build up than the water soluble type.
Date published: 2013-11-24
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