Using Muriatic Acid on 3GM30 Heat Exchanger

[terrylad]

Should I use a straight acid bath?

I tried a 50/50 water mix on the choked exhaust elbow to no effect. Straight acid worked great. Needless to say I flushed it out in salt water afterwards.

I'm just concerned about the acid working heavily on brass/bronze piping and aluminum end caps.

Appreciate your response.

This is yet another step in the unsolved issue of the engine missing after warmup at over 2K rpm.

[DotDun]

What are trying to clean? Soot? or barnacles?

For soot I would try a degreaser or mineral spirits

For barnacles I would use phosphoric acid (Barnacle Buster)

[terrylad]

I used straight hydrochloric acid (muriatic) for soot in the exhaust elbow. Worked great.

The heat exchanger has typical salt water calcium scale in the salt water pipes and general fine rusty scale in the fresh water section.

If there's a better product than a strong acid wash, let's know about it...

[lancelot9898]

I think that I've cleaned the heat exchanger 3 times over the 25 years that I've owned the boat. It's a Perkins 4-108. Each time I've used the muriatic acid and diluted it somewhat. Just don't remember how much, but the bottle may give some guidance. I used a watch to let it soak in the acid for around 2 or 3 minutes and afterwards used a baking soda solution to make sure all the acid is neutrilized prior to flushing with fresh water. I also used a rifle cleaning tool with a cloth to swap out each individual tube after the acid bath.

[Acushla]

When using acid cleans as part of a copper pipe cleaning regime on large generator cooling systems the mix was 10% acid to water, circulated continuouusly and maintained at 70 deg C for several hours

Acushla

[djmarchand]

Muriatic acid that is used to clean industrial equipment has an inhibitor that greatly reduces corrosion. I don't think that swimming pool muriatic acid has an inhibitor.

I would use Barnacle Buster, CLR, Rydlime, etc as those are milder and hopefully inhibited.

David

[gjordan]

When in out of the way places where the acids mentioned are not available, go to the local grocery store and buy several 2 liter bottles of diet cola. Make a tray/pan out of cardboard or anything available and line it with a garbage bag. Put inner parts of heat echanger in the tray and pour in the diet cola. It does an amazing job of cleaning the calcified interior,(and exterior) of the heat exchanger. I soaked mine twice and it did almost as good a job as the muriatic acid that I had used years before. YOU WILL NEVER DRINK DIET COLA AGAIN. It amazes me that human beings are allowed to drink that nasty stuff. ____Out of the way places make for out of the ordinary solutions.____Grant.

[DeepFrz]

White distilled vinegar is also good although not as strong as a product like Rydlime or CLR.

[Jim Cate]

Well Grant, I don't drink that stuff either, but do remember that your normal digestive processes involve HCl that is generated by your own gut, so our systems are pretty able to deal with mild corrosives!!

Fortunately, neither beer nor red wine contain such things...

Cheers,

Jim

[Doug Brown]

Hi - don't use muratic acid on aluminum parts - it will eat them up (speaking from experience...).

I use the straight strength available at hardware stores - I think it is about 34%.

Someone mentioned about a 2 to 3 minute soak for copper piping and this is a good number - it's what I used.

For heavy copper/bronze or steel parts I wouldn't go over 5 to 6 minutes before checking to see how things are going. Once the bubbling has stopped, most everything has been disolved.

Neutralize and flush with LOTS of fresh water.

Do NOT breath the fumes given off by the acid!!!!! They will really damage your airways and lungs. This is a kick-ass chemical, so be REALLY careful using it. Gloves and face mask with proper chemical elements in it are recommended too!