Thinking about carbs

[Administrator]

Originally Posted by HOTFLASH

I have the H2Out canister air vent dryer in my fuel vent hose to take care of the diurnal "breathing" in and out of air from the tank. In season or in winter. Inexpensive, easy to install and maintain. Won lots of awards 3-4 years ago.

Mary


http://www.h2out.com/air-vent-dryers

Hi, Mary:

Do you have any sense of how much water is captured by these devices, i.e., how much heavier is the old media than its replacement? Of course, all of the difference is not necessarily water, I guess.

Might these devices absorb water from the side opposite the tank, or are they "one-way" somehow?

Bill

[joe_db]

What I was wondering about was how often you change the material and how safe that is with gasoline. Unless I did some replumbing, I would be opening the gas tank vent to the interior of the boat.
Speaking of "both sides", on a Maryland humid summer day with 90%+ relative humidity, that thing could get a LOT of water from the overboard end of it.

Originally Posted by Administrator

Hi, Mary:

Do you have any sense of how much water is captured by these devices, i.e., how much heavier is the old media than its replacement? Of course, all of the difference is not necessarily water, I guess.

Might these devices absorb water from the side opposite the tank, or are they "one-way" somehow?

Bill

[HOTFLASH]

This product was developed in the Seattle area where the air is quite moist almost always. They have a variety of products. The one I was referring to is meant to put inline in the tank venting. in a place it would not likely have gas flowing. in any orientation (vertical or horizontal). I imagine they have a lot of experience with water vapor coming thru the venting there.

In Chicago, I have not yet in 2 years had to change the medium (it turns pink from blue when ready to change). I opened the container before I installed it to see and to feel the medium and to make sure it was easy to do remove the caps in order to dry it out the medium or change it when the time comes. The top and bottom caps are a rubber type material. And yes it would capture moisture in the atmosphere in the tank in so far as the air is expelled from the tank, but of course, water in the tank would be in the bottom of the tank. The H2Out site and the written materials offered are quite helpful I found. I have also called them. Unfortunately the lively and spunky fellow who developed the product and helped me became quite ill (nothing to do with the product) and may no longer be among us. I do not know for sure.

As for the difference in weight when saturated (pink), I suggest calling/emailing the company.

Hope this helps.

Mary

[Tim]

Practical Sailor did a test on the H2Out several years ago. Here is a PDF of the test.

[HalcyonS]

Originally Posted by Ball Racing

Alcohol will leave deposits of "things" in a fuel system if not flushed.
I ran methanol, and ethanol at 100% level in kart racing engines.
If you did not flush out the carb after the days events, within 3 days or so you starting building a gel, then it seemed start a chemical action with a zinc- or aluminum carb(depending on what yours was). You would then get white hard powder residue often followed by pits in the finish of the carb parts.
After a week or 2, chances are the needle and seat were stuck, and you had a big mess to clean up.
We used to flush them by running a mix of gas and marvel mystery oil at the end of the day.
Not 100% relevant to this discussion, but alcohol can make a mess.
The plus of its use was greater power, cooler running, and almost no carbon deposits.

Interesting. This gel/white powder/stuck needle story is very like my experience with A4 carb.

Will alcohol itself react with metals? I thought it was pretty inert in that sense. How pure was the alcohol you ran? Alcohol accepts water as we know, so the gel was probably residual water - but why did it separate out? Maybe issues with cooling from evaporation in the carb?

Reaction with alu/zinc/pot metal is plausible - who knows what impurities were in that stuff, in different batches. I don't recall my organic chemistry that well, but white powder sounds like insoluble salts off metal- like the pale green powder in my monel gas tank.

In any case, as Neil has pointed out, ethanol gas has - we believe - all kinds of proprietary additives in addition to ethanol.

[joe_db]

My aluminum fuel tank does not seem to suffer at all. The last time I looked inside of it the metal was corrosion free.
The carb - not so much
The carb has - AFAIK - zinc, aluminum, brass, and maybe a few other things in it. I suspect there is some kind of coating or plating or finish as well. It seemed to constantly get what looked like white toothpaste in it that would do a fine job of clogging things up. The substance either was created in the carb or somehow made it through 2 fuel filters. Nothing solved it for good but a new carb and repeat this exact experience on a friend's boat as well. I expect in 5 or 10 years I might see this issue again, except now I run Seafoam, which did well in Practical Sailor tests in preventing this issue.
Some google-fu will show this issue is not unique to A4s.

Originally Posted by HalcyonS

Interesting. This gel/white powder/stuck needle story is very like my experience with A4 carb.

Will alcohol itself react with metals? I thought it was pretty inert in that sense. How pure was the alcohol you ran? Alcohol accepts water as we know, so the gel was probably residual water - but why did it separate out? Maybe issues with cooling from evaporation in the carb?

Reaction with alu/zinc/pot metal is plausible - who knows what impurities were in that stuff, in different batches. I don't recall my organic chemistry that well, but white powder sounds like insoluble salts off metal- like the pale green powder in my monel gas tank.

In any case, as Neil has pointed out, ethanol gas has - we believe - all kinds of proprietary additives in addition to ethanol.

[Al Schober]

FWIW, I've had one (at least) case of the carb being fouled by corrosion products from the case of the secondary fuel filter. The steel filter case was corroding, and the corrosion products downstream of the element went straight to the carb.

[HalcyonS]

Originally Posted by Tim

Practical Sailor did a test on the H2Out several years ago. Here is a PDF of the test.

Thankyou! This line was particularly relevant:
"In ethanol gasoline
(E10) systems, even the smallest amount of moisture can corrode aluminum, copper, steel, and zinc, gumming up
passages and needle valves in carburetors."

[HalcyonS]

Originally Posted by joe_db

It seemed to constantly get what looked like white toothpaste in it that would do a fine job of clogging things up. The substance either was created in the carb or somehow made it through 2 fuel filters. Nothing solved it for good but a new carb and repeat this exact experience on a friend's boat as well. I expect in 5 or 10 years I might see this issue again, except now I run Seafoam, which did well in Practical Sailor tests in preventing this issue..

"The substance either was created in the carb or somehow made it through 2 fuel filters"
my experience too.
" I run Seafoam, which did well in Practical Sailor tests in preventing this issue."
what exactly did the sea foam do? Do you have the ref?
thx

[ndutton]

Originally Posted by HalcyonS

Thankyou! This line was particularly relevant:
"In ethanol gasoline
(E10) systems, even the smallest amount of moisture can corrode aluminum, copper, steel, and zinc, gumming up passages and needle valves in carburetors."

I'll keep asking the same questions. Assuming you have water in your E10, where did it come from? Tank incursion? Humid vent air? You and I live in the same climate, why aren't our symptoms the same?

In the combination of threads covering this problem for the past year there has been a consistent assumption that the carburetor metal is reacting with E10 fuel and/or the contaminants within. If you're headed toward carburetor replacement anyway sooner or later as has been suggested more than once, why not sooner?

[joe_db]

Practical Sailor tested all the common gas additives for dealing with long term storage issues. One of the issues was aluminum corrosion and Sea Foam was second best at preventing this. BioBor* gasoline additive was better but much more expensive.
I read this as a hard copy the local Western Auto had printed out. I don't think you can get it online without being a paid subscriber.

* Biobor was best at ALL functions of fuel preservation. SeaFoam was decent at all of them and 2nd best with aluminum. Startron was rather unique at dealing with water issues well but pretty much ignoring other fuel issues. For this winter I am using Seafoam and Startron. When my Startron gets used up it might be Biobor next winter. Also note the local outboard shop suggests using Seafoam FWIW.

Here is a photo that more or less shows what I was finding:


Here is a link for subscribers:
http://www.practical-sailor.com/issu...n_10855-1.html

There is a brief summary you can see for 20 seconds or so that I screen-captured. This is NOT the full article, which I cannot get to.

Originally Posted by HalcyonS

"The substance either was created in the carb or somehow made it through 2 fuel filters"
my experience too.
" I run Seafoam, which did well in Practical Sailor tests in preventing this issue."
what exactly did the sea foam do? Do you have the ref?
thx

[Tim]

Here is the full article and summary chart from Practical Sailor.

[HOTFLASH]

Note that the treatment cost per gallon of gas for the Biobor is only 7 cents so it is not really so expensive, unless I am missing something.

Mary

[Tim]

Also note that Practical Sailor found no issues with the E-10 fuel itself. The problems occur when the fuel is contaminated with water or when incompatible materials are used in the fuel system(fiberglass tanks, non alcohol rated fuel lines...).

[joe_db]

I am hoping the white goo will not come back since I got a new fuel fill cap. The powers of ethanol to cause problems seem weak unless aided by water.

Originally Posted by Tim

Also note that Practical Sailor found no issues with the E-10 fuel itself. The problems occur when the fuel is contaminated with water or when incompatible materials are used in the fuel system(fiberglass tanks, non alcohol rated fuel lines...).

[HalcyonS]

"cooling induced phase separation"
Makes sense in the carb, auto-refrigerating itself.
Hmmm, I seem to recall some carbs (in MGs?) were heated by engine cooling water - now there's an interesting project
I did a high concentration seafoam flush a few months ago. I think I'll try it as an additive.