Selleys "knead It - Aqua" Ok To Use In My Boiler?

[Jez]

Howdy,

I'm in the process of trying to block up the drain hole in my "Malleys-type" stainless electric boiler (since I can't unscrew the damn thing!) and no matter what I do it still seems to leak. I've wedged a piece of a tight-fitting stainless bolt in the hole & have used silver solder seal it up but it still leaks.

I've seen mention of selleys "knead it" being food safe & the selleys website says it can take temps up to 120 degrees.

I bought some of the "knead it - Aqua" this arvo on spec. Do you reckon I should be ok to use this stuff to finish sealing the drainhole?

Thanks

Jez

 

[Jez]

sorry, here's a link to the product.

http://www.selleys.com.au/products/live/308/113.asp#uses



Jez

 

[Fingerlickin_B]

I reckon you should just braise it

Kneadit may be "food safe", but I thought it was a semi-porus epoxy-based product?

PZ.

 

[Fingerlickin_B]

And for my "think before posting" follow-up post...

Yes, I know brass is porus to a certain degree, but it shouldn't pose a leakage problem if you braise.

Regarding the silver soldering...what kind of heat did you apply when doing this...and what flux did you use?

PZ.

 

[big d]

can you post some pics jez of the offending bit.it may help with ideas.personally i dont like the idea of using these products due to the possibility of chemical leaching into your wort.
as they say pics are worth a thousand words and in sure we all can come up with some ideas.


cheers
big d

 

[Ross]

Jez,

It works great - it is the ONLY product selley sell that they guarentee as being totally food safe in hot water - Even their aquarium sealent which i was original going to use, they would not rate as safe...

 

[Jez]

Thanks for the input Ross - I too was thinking about using their aquarium sealant as a backup if Knead It was not safe (since it's supposed to handle up to 160 degrees). Now I won't. How did you use Knead It in your boiler - how longs it been in there & any problems? The piece I'm trying to seal appears to be brass but that shouldn't matter should it?

Fingerlickin - I bought a MAPPS-type gas burner from Bunnings last weekend and used that to heat up the flux-covered part & the solder. The flux & silver solder I used came together in the "Plumbers Lead Free Silver Solder" kit I got from Bunnings for about $23 or so. The problem I'm having is that the part I'm trying to solder is circular so once the solder becomes liquid it slides off. The other prob I have is, whilst I have a little electronic soldering experience, I have no experience with this these burners and don't really know what I'm doing

Maybe my soldering effort was crap & I just need to have another go at soldering it up properly.....

Big D - I'll try to post some pics tonight when I get home.

Any advice would be greatly appreciated. It's really starting to shit me as on Monday I took delivery of my keep Cold cooler & 6 metre CFC from Goliath & this leaky boiler is almost the last piece in the puzzle before I can do my first AG. Can't wait to try Jase's Skunk Fart recipe :beerbang:

Jez

 

[Borret]

I Doubt very much if plumber's lead free solder will attach to stainless and this is why it is balling up and running off. You will need to buy a brazing rod specifically formulated for stainless. The other probelem here is that these types of brazes often contain cadnium which is not nice stuff. So carefull selection is the key.

I am not a fan of using kneed-it personally. Although water safe/ food grade it is still an epoxy based (I assume) product which I would prefer to keep away from my beer. Depending on your attention to 'knneding' it there is a chance (although very small) of uncured product also.

My advice, (take it or leave it as you please) is to revisit the brazing option if you've got a torch and select the right brazing rod. You may find CIG have a flux coated rod fit for purpose so you don't need to worry about additional paste.

Cheers

Borret

 

[Ross]

Jez,

I haven't used it in my mash tun - I have used it to seal the ends of all my S/S temperature probes which sit in my HLT , mash tun, boiler & fermenters - & to date no problems.

How well it will work in your instance I am not quite sure, though I'm sure it would work, I was really responding to the food grade side of it - Selleys technical department were adamant that it was totally safe...

P.S. It sets very quickly, so make sure you have a plan before mixing...

 

[Jez]

Thanks Ross & Borrett

The part I need to seal is brass not stainless. The solder should stick to brass right?

I probably just need to have another crack at silver soldering it again and do a better job.

 

[Borret]

Thanks Ross & Borrett

The part I need to seal is brass not stainless. The solder should stick to brass right?

I probably just need to have another crack at silver soldering it again and do a better job.

[post="78448"][/post]​

If it's just brass then you should have no probs. Properly cleaning the joint and applying flux effectively is the only thing it could come down to then. Perhaps just do a google on brazing technique, see where yours vary's and your problem may be solved.

Good luck

Borret

 

[Jez]

Great idea. Dunno why I forgot about my friend Google.

Thanks Borrett.

Jez

 

[Justin]

Yeah brass should be a walk in the park, you can also use just normal lead free solder (Aquasafe 100-combination of Zn and tin, no lead or cadmium) if what you have is REAL silver solder and your having trouble. You also should get plenty of heat from the MAPP gas torch. I solder brass and copper with my Propane Bernzomatic with no worries but it doesn't have the heat to braze or silver solder, but MAPP supposedly does.

Just clean the surface of the brass up with a wire brush or sand paper to get it clean. Sometimes helps to give it a wipe over with acetone. Depending if you've got paste or liquid flux, heat and apply the solder. Should run like water.

Keep trying and/or practice on some other bits and pieces lying around. Just remember the piece your heating sounds pretty big and it can absorb a lot of heat (great conductor of heat) but I'm certain with MAPP you'll have enough heat to do the job.

Let us know how it goes.

 

[Jez]

will do justin. thanks.

Jez

 

[timmy]

use the metal to melt the solder, not the flame.

 

[altstart]

:beer:
Gooday Jez
I have used food grade silver solder on stainless. I did some research with BOCs technical department and after finally locating someone who had the correct information I bought the correct grade silver solder and flux. The silver solder sticks have a white tip on the end to signify they are food grade and completely cadmium free. I used Oxy Acetylene to do the job and I was surprised how hot I had to get the stainless before applying the silver. The flux is a general purpose grade. Hope this is some help to you.
Cheers Altstart

 

[Jazman]

you could use stainless flux for soldering as i do soft soldering some times but u should get some hydrocloric acid and put it on some scrap steel like stainless to kill the spirits, then with a brush apply to the joint then try to weld it so u remove any protective layer but i knowt works with soft soldier and i reckon that soft solder would melt with those burners we use

 

[Plastic Man]

Just back to the selleys part of the thread

I used some selleys roof and gutter sealant in a garden sprayer keg I made. I called the Selleys support line before I used it to ask what silicon sealant was food safe. The guy I talked to said that even though they dont say it on the pack, the roof and gutter sealant is food safe and rated at a decently high temp. The reason he gave me was that because it is used a lot on steel roofs, a lot of people collect their water off the roofs so its food safe. Also OK at high temps as it needs to sit in the sun on a hot roof.

I havent actually used the keg yet as I couldnt get the tap to stop leaking so was going to put a picnic tap on it. I then I had to move into a small flat temporarily so all projects are in storage for a month or so until I move again, (3 small kids in a 2 bedroom flat ahhhh!!). Any thoughts. Have I been sold a bum steer ??

 

[Borret]

Sounds like he was selling something!

The way I reckon you've got to look at all this is-

If you made a cup out of any of these products would you be happy drinking your acidic beer out of it every day. If the answer is no, then find another solution 'cause that's effectively what you are doing. If it is yes then drink on.

My last 2c spent on the subject

Borret

 

[Plastic Man]

Borret

Not a bad way at looking at it.

cheers