DD formula for cleaning heat exchangers

[Toolsntoys]

Hello all I have been reading all the past threads on cleaning heat exchangers. I see many different ways and possibilities. My question is what is the exact formula DD recommends? I thought I had saved it but went back looking for it and couldn't find it. I also searched the manual and didn't find it. I must be blind. Lol. I really want to remove the HE and do a visual inspection before and after. I will be moving the boat to its new home in June (about 300 miles) and plan on going though things top to bottom before the trip. Thanks. Pete.

 

[racclarkson@gmail.com]

Detroit didn't make the HEs on my boat. That's probably why you didn't see it in the manual. There's new stuff out there since the paleolithic era when the motors were built. I've used Barnacle Buster twice and can't find any fault other than the cost.

 

[Toolsntoys]

I know it's muriatic acid mixed with water and half pound oxalic acid to 2.5 gallons of the mixture. It is cheaper and works faster then barnicle buster from what I hear.

 

[Bob Bradley]

I was told to flush the heat exchangers with a solution of 1 part Muriatic acid, 2 parts H2O, and 1/2 lb oxalic acid to make 2.5 gal total. I calculate that to be a tad over .8 gal of muriatic and 1.6 gal water. I think I used a full gal of Muriatic and 2 gals of h2o and just bumped up the oxalic a bit to make measuring easier and to not wind up with .2 gal of acid left over and laying around.

Wear eye projection, rubber gloves and a heavy old shirt and pants. I also keep a solution of baking soda and water readily available in case I get any on me.

And, always pour the acid into the water, not the other way around (see: http://antoine.frostburg.edu/chem/senese/101/safety/faq/always-add-acid.shtml).

That said, keep in mind that if you pour acid into water and it splashes up, it will be the acid that splashes up, not the water. I know that from pouring chlorine shock into the pool.

 

[Toolsntoys]

Bob thanks for the advise. I'll give it a try.

 

[bobk]

Be sure you use the acid off the boat. The fumes are very coorosive.

Bobk

 

[MikeP]

I have always used the DD muriatic/oxalic recommendations contained in the DD service manual, which are as Bob described. Works great and is very quick. Obviously, it requires pulling the HEs, which is also what DD recommends. I do it every couple years. I know many folks like the in-place cleaning but I prefer the DD method because I like seeing what everything looks like. The HEs look brand new after the cleaning.

 

[Fair Well]

I'm like MikeP I like to see everything that being said hears some pic's of a little experiment I did. This is with the newer environmentally friendly stuff I bought. I circulated for 45 minutes in reverse flow. I have to say I was impressed with it no longer then I circulated it. The guy where I bought it told to circulate for around 2 hours. I had a sea cock that didn't seal so I was losing it out the bottom of the boat and had to stop. (hence environmentally friendly ) This is on a 12V71TA. I well get the name of the stuff and try to post next week. They sell it by the gallon out of a 55 gallon barrel. You do not mix or dilute ready to use.

 

[SEVEN]

The HE look great. Are you in salt or fresh water? How long ago did you last have them cleaned?

 

[Fair Well]

The HE look great. Are you in salt or fresh water? How long ago did you last have them cleaned?

I'm in salt water. The pic's are before and right after cleaning. It been about two years sense I cleaned them.