Hydrochoric Acid Concentration

Ian_Rob

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I have a litre of 35%-36.6% Hydrochloric acid which I intend to mix with water for cleaning the insert of the heat exchanger of my Volvo D1-30B.

Any suggestions as to what is likely to be the working concentration I should use?
 
Id dilute it around 10 x , ( ie ending up with about 3.5%)

make it more dilute, up to 20x, if the scaling is light .

Add the add to the water.... not because it'll get very hot like sulfuric acid does but because if you add water to the acid youll get clouds of HCl fumes. ( It'll get fairly warm though.)

Personally id use a domestic scale remover such as Killrock K or Mega K ( which are formic acid based) or a central heating boiler descaler such as Fernox DS-3 ( which is sulfamic acid based)
 
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That sounds like the maximum concentration achievable so you are dealing with extremely aggressive stuff.

I would dilute that down by about 5:1 so you have something safer to handle ..... but be careful during the dilution phase.

Richard
 
That sounds like the maximum concentration achievable so you are dealing with extremely aggressive stuff.

I would dilute that down by about 5:1 so you have something safer to handle ..... but be careful during the dilution phase.

Richard

Its unpleasant to say the least.
In the lab you'd normally open a "Winchester" ,and do the dilution, in a fume cupboard.

( also available as "fuming hydrochloric acid" which is about 40% ..... I don't think I've ever used it though
 
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It sounds like I need to be extremely careful. I think i might try some Mega K first and see how that deals with the build up.

I am not sure what the insert is made of. Is there any potential for damaging the assembly with Mega K? I used Rydlyme on the hub of my two blade folding prop a few ago only to find that I had eroded the splined aluminium core.

THANKYOU
 
I'd be very surprised if the pipe-stack/insert is not copper tubes with DZR brass flanges, or perhaps bronze flanges; either way yellow metal all round. Unlikely to be harmed by any common descaling fluid.
 
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It sounds like I need to be extremely careful. I think i might try some Mega K first and see how that deals with the build up.

I am not sure what the insert is made of. Is there any potential for damaging the assembly with Mega K? I used Rydlyme on the hub of my two blade folding prop a few ago only to find that I had eroded the splined aluminium core.

Yes, you do need to be careful! Rubber gloves, eye protection, lots of ventilation. Mega K is simply a larger bottle of Kilrock-K (1 litre vs 250ml), the concentration of formic acid is the same. For your use, I reckon a 250ml bottle of Kilrock-K would be fine. You need to dilute it; 1 part Kilrock-K to say 5 parts warm water.

Kilrock-K shouldn't damage your heat exchanger, but it may turn copper and brass black.
 
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