Results of heat exchanger flushing

[Canuck Dennis]

Stb'd was running too hot, took out the plug that holds the zinc in the s/w intake , connected hose and funnel, idle speed, ran two galls phospho thro, kept idle for 2 or 3 more minutes amazing results, no apparent side effects yet.

 

[Vincentc]

Dennis,
Was this a single pass of undiluted acid?
What were the interesting results?
Regards

 

[MikeP]

Please confirm or correct:

You attached the hose/funnel to the HE at the zinc fitting on the intake side of the HE, stared the engine and ran at idle so raw water was going through the HE as normal and then poured 2 gal of phosphoric into the funnel/HE with the engine running at idle for that period?

What was the temp difference at cruise or WOT after that cleaning?

I find it interesting because it is really easy but I have to admit that at the same time, I wouldn't expect it to actually work due to the relatively small amount of fairly weak acid vs the RW and the limited time involved. But if it DOES work well, that's great and by far the easiest method I have seen.

I always remove the HEs and dunk them per DD's shop manual recommendation so your way would be a lot easier/faster!

This added later: I'm surprised there wasn't enough RW pressure to pump water up the funnel hose but obviously if there was, you couldn't have dumped the acid in (if I'm understanding the method you used).

 

[Canuck Dennis]

Connected at the r.w .impeller intake, used undiluted phospho and just let it idle thro along with the sea water, I would say a good 20 deg diff at 1300 rpm have not yet ran up to wot, but at 1300 before we were starting to run up to 200 deg. and a bit higher, then I would shut it down and run on one...

 

[Tinman]

That almost sounds too easy. What were the results? Recently, I was talking to Gulf Coast Hatteras and they have put together a 25 gal. reservoir and pump that can be plumbed to the HE and cleaned in the boat without the expensive R&R. Not sure which cleaner/descaler solution they use, but will ask next time we talk. This is an interesting subject because I have always wondered why HE's and coolers could not be cleaned in place with a safe solution.

 

[Canuck Dennis]

we did this in st Petersburg, I asked the local mechanics what they used and charged , said 900.00 per engine and hooked up the circulating system, at that point I thought a 40.00 try would be no big loss. It's important that you connect to the suction side of the r/w impeller ot it might just blow back at you.

 

[Tinman]

we did this in st Petersburg, I asked the local mechanics what they used and charged , said 900.00 per engine and hooked up the circulating system, at that point I thought a 40.00 try would be no big loss. It's important that you connect to the suction side of the r/w impeller ot it might just blow back at you.

Good idea. Apparently did the job? $900 sounds a little stiff per engine. Cleaning the HE should be the same as an A/C. Plumbing it would be the most work.

 

[Tinman]

Dennis,
I just checked my HE's, your setup will not work for mine, but with the right fittings it would be an easy setup to circulate a cleaner/descaler thru and retrieve most of the solution. If my temps start creeping up I will try it. Probably already have most of the hose, fittings, and pump to do it. Thanks for the heads up on this.

Roger

 

[bobk]

No need to reinvent the wheel.

http://www.samsmarine.com/forums/sh...-Exchangers&highlight=cleaning+heat+exchanger

 

[Tinman]

No need to reinvent the wheel.

http://www.samsmarine.com/forums/sh...-Exchangers&highlight=cleaning+heat+exchanger

Thanks for that link, great post.

 

[MikeP]

Circulating the acid has been used extensively as noted but CanuckDs method is far easier and, IMO, worth a try. THe circulating method will certainly work but I have always been put off by the necessary plumbing to be fabricated. A fitting in the RW pump, a piece hose and a funnel makes it almost a non-job. The entire process is the time it takes to pour the acid in the funnel.

It might cause me to abandon by periodic pulling/boiling out the HEs...

 

[bobk]

Circulating the acid has been used extensively as noted but CanuckDs method is far easier and, IMO, worth a try. THe circulating method will certainly work but I have always been put off by the necessary plumbing to be fabricated. A fitting in the RW pump, a piece hose and a funnel makes it almost a non-job. The entire process is the time it takes to pour the acid in the funnel.

It might cause me to abandon by periodic pulling/boiling out the HEs...

Mike, It's going to come down to how bad the fouling is. If not too bad, sure a short exposure to acid will make an improvement. If it hasn't been done in a while, maybe not.

 

[SKYCHENEY]

Two things:

1) I can't believe this worked as the only way I have done it is with a bucket of diluted Ospho and a pump and let it run for 45min. It doesn't seem that the concentration would be strong enough or
stay in there long enough with the approach that Dennis used. But, apparently it worked for him.

2) Since this is a phosphate, you aren't supposed to let it go into the water as it promotes weed growth. If you don't recapture it, you can't disposed of it properly. BTW, it makes a great fertilizer.

 

[Paul45c]

Circulating the acid has been used extensively as noted but CanuckDs method is far easier and, IMO, worth a try. THe circulating method will certainly work but I have always been put off by the necessary plumbing to be fabricated. A fitting in the RW pump, a piece hose and a funnel makes it almost a non-job. The entire process is the time it takes to pour the acid in the funnel.

It might cause me to abandon by periodic pulling/boiling out the HEs...

IMHO, the in-place flushing has always worked great (thanks, Genesis! and this idea sounds cool, too), but just bear in mind that the H/E bolts need to be freed up and have a new coating of anti-seize periodically. Leaving those in place indefinitely and risking a seized and broken off bolt in the casting can really create Excedrin Headache #7.

You doing it the old school way is, of course, the surest thing. Personally, I think a blend of both methods works...maybe do the total removal and dunk once, in-place flush twice, go back to the dunk, etc.

 

[Tinman]

Found this site while researching how to clean my Caterpillar plate type H/E's in place. Good info and professional. Check the rates for engine, gen, & a/c package for those that do not want to diy. Basically the same procedure as Genesis plus cleaning coolers at the same time. He did not identify the cleaning solution, but sounds similar to Triton Marine Engine Flush.

http://overtempmarine.com/