Heat Exchanger cleaning question

[DCatSea]

Does anyone have recommendations for flushing out the heat exchanger on a 4D61?. I am applying liberal amounts of TLC to this, after, I suspect, years of neglect. Once off, it turned out to be in better shape than I had hoped for - could still see through it, no barnacles or POs inside etc, but no zincs to speak off, ghastly gaskets and generally cruddy.
A thorough cosmetic clean and it's ready for the next stage - flushing out - and therein lies the question: What have other AOGers used to do this themselves. I could pay the marina mechanics to do it, but I'm cheap, and they are not. Recommendations for flushing fluids range from RydLyme, which I gather is option #1 but difficult to track down, to muriatic acid solution, and on to CLR (this BTW states clearly - "Do Not Use on Copper Items".

So - recommendations for DIY Exchanger flush out juice?

Here are some "before" and "next stage" pix.

Doug

[DCatSea]

Lehman manual says to run a 3/16 wooden dowel down each capillary; and I have heard of a .22 calibre cleaning kit doing the job, but I am dubious of putting anything down the tubes for fear of causing damage. Any comments?

[TorreyWP]

I brought mine to a local engine rebuild/machine shop that used a boiling process boil clean it. I never asked if it was a chemical or just boiling agitated water that scrubbed everything off and I mean everything inside and out, paint and all. It appeared shinny new when I picked it up. I assume a radiator shop might be able to do the same.

By the way, I can't shake my frugal New England upbringing (read: I'm also cheap). I would suggest some phone calls to shops that do that sort of stuff in your area, I'm sure you can find someone willing. Heat exchangers are delicate and made of expensive metals; my advice would be let a pro handle it before you going stabbing at it! I paid 50 bucks and pick it up the next day.

Good luck!

[WillieC]

I found some plastic rod in a coil my dad had left in the shop. Not sure what it was but it fit the tubes pretty good. My Sendure HX has only one removable end and a pencil zinc in the other, but i was able to rod it out pretty good.. Made my own end gasket out of an Ace Hardware gasket kit. Slapped it back together, no problems. (Or a radiator shop boil out and pressure test, cheap, easy, and they know what metals they are dealing with.)

[jleonard]

I have used a 22 cal cleaning rod/brush and have no issues with damage being careful. I also use a piece of brazing rod if there is some debris partially filling the tube.
After I clean mechanically, I flush with water then use a little bit of muriatic acid and let that drizzle thru for maybe 30 seconds, then I flush thoroughly with water.
Then re-assemble and paint.

[Pitou]

I've also used a .22 cleaning rod with bronze brush when the HX was still mounted on the engine. With it off, bathe the HX in 10% HCL to 90% water +/- and let it soak for an hour or two and rinse thoroughly. Repeat if necessary and repaint. I did the HCL/Water soak and rinse on the HX of my Etec generator in my 28 and it came out scrub a dub clean.

[DCatSea]

Some excellent advice from AOGers, as usual. I will try the very careful .22 bronze brush (with brazing rod standby, and HCL flush out.

Best to all - wish I was in the water this weekend.

Doug

[WillieC]

Looking for bottom paint tips I found this:

http://www.pbase.com/mainecruising/heat_exchanger

I think that is your HX.

[rebuckley]

Great to see the suggestions for cleaning, as this is on my list for this spring as well.
I did have 2 questions (and mainly because I have not crawled behind the engine yet) - how easy/hard is the removal? Assuming no changes to the mounting - I was expecting to see 2 strap brackets holding it on, yet I could not see them from above. (I assumed this as when I did pull my generator HX, it had the straps and 4 bolts) just wondering how the removal is going to go on the Lehman? Second question, assuming the HX is fine, just the gaskets and end plates are messed up - does anyone know a good website for replacements of the gaskets (and end caps - although I assume these are fine if the HX is still serviceable)

[DCatSea]

With the Lehman 4D61, the HX came off fairly easily. In my case it was super easy; HX was held on by 4 stainless hose clamps. Now I'm looking for more substantial OEM-type heavier-duty steel clamps (any suggestions most welcome - may end up fabricating them). Like my installation, I have seen pix on AOG for 4D61 HXs being separated from oil filter by rubber material clamped in place, because of "sagging" of the clamps. (Working on that.)

I think the biggest additional task is that removal of hoses is a golden opportunity to replace them all with new ones. For the Lehman this presents a "where do I get them" problem, but this is not insurmountable. I am "just" going to take the old ones to an automotive store and get matches - (I DO know that one is a direct match for a '69 T-Bird hose, and can be cut to fit).

Gaskets for the end caps seem to be readily available from HX manufactures, and are probably interchangeable or adaptable.

I will post an update on the hoses.

[DCatSea]

WillieC - Thank you very much. A useful resource that I had entirely forgotten about. It is now in my Favorites Bar.

Additionally - I have just posted the "Lehman Parts Identification" manual to AOG Manuals and Tech Docs forum.

Doug

[denchen]

This looks like the sort of crud Coca Cola would shift with a soak.

[DCatSea]

Denchen - that's a really good, long-forgotten, point. HP sauce used to do the same thing, with advantage of being sticky. It would be messy as hell.

[tego]

Coca Cola has a pH of about 4.0, so it's definitely acidic. It contains phosphoric acid, which is one of the few acids that can be used on aluminum. I'd still use something a bit stronger which won't leave a residue. CLR contains sulfamic acid, which is a fairly safe acid-you still need safety goggles on your eyes-but it'll clean your HE a lot faster. Mix it with hot water about 50-50 and it should do yours in about 15-20 minutes. Rinse well afterwards. Ben

[Neil]

Ive used barnacle buster with good success. I stood it up with one cap on and filled it, it bubbled and sizzled for a couple hours then I dumped, flushed ,and used a .22 cal gun kit. It all went fine.