Semi-Annual Vinegar Flush and other question

[Kurt]

So, this weekend I did a Muriatic acid flush on my late model Atomic 4 and then proceeded to do the pressure water flush with a kit purchased from Moyer. That was a pretty tough/time consuming job and I'm sure glad I'll only have to do it once every three years! 2 questions. When I flushed the aft section of the block (water intake in aft drain hole), the discharge water ran perfectly clear - no crud at all. When I flushed the forward section, it was so plugged that I only got a trickle of water at the discharge hose. After probing in that hole with a coat hanger and flushing again, it worked and a bunch of black crud came out. Is that normal to have one section of the block run clear and the other be filled with crud?

Also, the previous owner of this engine flushed the block with 2 gallons of straight vinegar twice a year using a T valve arrangement. He only let it sit for about 2 hours each time. I was wondering if I can keep my cooling passages in better shape by letting 2 gallons of straight vinegar sit in the engine for about 12 hours twice a year. Is there any possible risk to doing this? I was amazed at what 12 hours of vinegar soaking did to my incredibly gunked up thermostat (it went from looking like trash to looking brand new) so I was thinking that it might really clean up the cooling passages of the engine too.

Appreciate any insight.

[luvmyi36]

Kurt,

I do not have any insight to your question, just thought I would give it a bump because I would like to hear thoughts on this as well!

[Chris T]

Vinegar Flush

I fill and soak my FWC in vinegar and it cleans very well. I can't see a problem here as it's biodegradable. Chris

[forcenine]

Hurrah for Vinegar

I'm cleaning up crud all the time with vinegar now.

I did a muratic flush previously, which apparently blew blockages from aft block drain hole, and in my haste to wipe up the liquid spewed everywhere I breathed in the acid steaming off the engine. Of course my bilge blower was not operating at the time. Sent me to the doctor for an X ray and had to use an inhaler for 2 weeks to clear lungs. Long live granny's vinegar.

[Fred]

Can you do this vinegar wash while the boat is in the water, let it run through the cooling system and let it stand for a couple of hours?

When you run the engine to flush out the vinegar, will it have any adverse effects to the lake?

We certainly ingest enough of it ourselves.

[Rick_Powers]

Acetic Acid Rinse

I have had good results with Acetic Acid ( (HAc) or (Vinager) ).

I am lucky to work in a biotech lab, so I can get Glacial Acetic Acid for free.

I took some concentrate, diluted it to ~10%.

Next I closed the water pump through hull, and disconnected that hose from the water pump.

After attaching a longer temporary hose to the water pump I put the end of the hose in a bucket of HAc, ran it through, let it soak, then replumbed and rinsed with salt water (SF Bay).

Vinager is a naturally occuring compound and dilutes and biodegrades easily.

[Kurt]

I have always done the vinegar flush with the boat in the water. I don't see any harm to letting the vinegar solution go out into the lake. It is a natural substance and will get diluted quickly. The A4 cooling doesn't have such a large capacity to result in anymore than 2 gallons or so leaving the system and going into the lake. Muriatic Acid is probably more of an environmental concern, although the acid is neutralized pretty quickly by water.

Just my take on it. I would be much more concerned about things like oil, sewage and fuel ending up in the water.

[Mark S]

Kurt, how long to you leave the vinegar in the engine? Mark S

[Baltimore Sailor]

In this forum most suggest to leave the vinegar in for about 24 hours, or at least overnight.

[Dave Neptune]

Vinegar

I have used it in the my salt water cooled A-4 a few times. I do an acid flush whenever the engine starts to run warm and the bypass valve (no thermostat) won't keep the engine cool every 4-5 years sometimes longer between. I put the vinegar in about once every year or so the same way I do the acid flush. I use a 5 gallon bucket, put the water intake in the bucket and also put the exit line at the rear of the intake manifold in the same bucket and fire her up. I let her run for a while at idle until the bucket starts to warm up, shut her down and wait a day or three. I then reconnect and start her with the salt water to flush the vinegar. When I do the acid I don't run the engine I use a recirculating pump and bypass the water pump to keep the acid out of it. I run that for an hour or so then disconnect and hook up the salt water to flush.
The vinegar is good for cleaning all sorts of salt water corrosion away even in the head. It works wonders in the head by making the boat smell like a salad instead of a "porta-potty". I have recently installed an electric head (fourth year starting the fifth) for the wife and the vinegar seems to keep it running fine, ie no problems with the pump. I think it may be that the vinegar keeps the solids that form from the salt out thereby adding life to the electric pump. I had many friends tell me to stick with the manual because I would be replacing the pump every other year or so, NOT YET.

David Neptune

[Baltimore Sailor]

Why do you go to the trouble of running the outflow line back into the bucket? It seems to me all you really need to do is run the engine until it's warm, then put the intake hose in the bucket and suck in about three gallons of vinegar. The heat of the engine is going to warm up the vinegar anyway as it sits, and you wouldn't have to fuss with another hose connection.

[Dave Neptune]

The bucket

Baltimore, I use the bucket so the liquid acid or vinegar actually circulates and gets into everything. It also gives a good idea as to how much gunk is broken loose and gives much of it a place to settle. I was doing a flush on a friends boat that had been neglected and while trying to get it to circulate it actually kept plugging up where it comes out of the manifold. At least while we were doing the flush we could stop and break things loose with a wire.
I feel that by circulating it gets into everything a lot better. Besides it's just two hoses and I think a little heat helps. Besides on my ole E-35 the engine is in the middle of the boat which makes access very easy.
David

[Kurt]

Mark - to answer your question - I used to do the Vinegar flush twice a year (fall and spring) and would leave it in the engine for about 3 hours - sometimes a couple hours longer. Even with that amount of time, I would always get gunk out of the engine upon start up after the flush. I recently converted my engine to fresh water cooled as I got sick of doing vinegar flushes, acid flushes and pressure flushes. Just a note on these flushes: when I took off my water jacket side plate to clean the cooling passages as well as I could prior to the FWC conversion, I was amazed at how clean they were after 32 years of raw water cooling. There was some black gunk and rust chips, but nothing like the nightmare I expected. I know the previous owner always did twice annual vinegar flushes so I would imagine that is the reason for the good condition of the cooling passages on this motor. He never did an acid flush. So, these flushes are definitely good cooling system maintenance.

[Delphis]

Vinegar Flush

Is there any drawback to just running vinegar in through the FW inake and out the exhaust? It seems the vinegar would ungoo parts of the manifiold as well, no?

[Rbyham]

Bringing this older thread back. About to do my first vinegar flush on an A4 that runs fine. Just sounds like basic maintenance that we ought to do as we head into cooler days here. One question I have is where does one get gallons of vinegar? My grocery store only sells the smaller bottles. Do I dilute it or put in straight vinegar? Thanks...