777Dave

777Dave

Well Known Member
I am in the process of purchasing an '91 RV-4 and was wondering how/why/when slosh becomes an issue? This a/c has slosh inside the tanks but
shows no signs of residue in the tanks or drains or gascolator. Should I anticipate future issues? Is there anything I can do to prevent a problem?

Dave
 
It becomes an issue when it flakes off and makes its way to the filters. If you cant chip it off with a screwdriver I would not loose any sleep over it for a long time to come.
Even for those that are chipping, proper filter maint will keep the engine running. I would not hesitate to fly a sloshed 4 even that is chipping off. I know cause I do it all the time.

Best,
 
Probably a dumb question....

What in the world is SLOSH, and filter? eh..what filter?

I have a 2003 RV6 that has a gascolator, but no filter.. I want to try and avoid being an accident waiting to happen..:-(

H.
 
hughfi said:
What in the world is SLOSH, and filter? eh..what filter?

I have a 2003 RV6 that has a calculator, but no filter.. I want to try and avoid being an accident waiting to happen..:-(

H.
Click to expand...

Slosh was an added coating in early RV's. You poured it into a finished tank, and sloshed it around. Since it started to flake, the practice was abandoned.

With a gascolator, you don't need an additional filter, unless one is required for an in-line fuel monitor ---- which many RV's don't have either.

L.Adamson
 
Slosh may be brushed on...

L.Adamson said:
Slosh was an added coating in early RV's. You poured it into a finished tank, and sloshed it around. Since it started to flake, the practice was abandoned.

With a gascolator, you don't need an additional filter, unless one is required for an in-line fuel monitor ---- which many RV's don't have either.

L.Adamson
Click to expand...

There also was a second option recommended by Vans. If the tanks were not yet sealed, the process was to brush several layers of the white slosh over the top of the ProSeal only.

This is what i did to one of my tanks - and I'm removing it now - It's a real pain in the #$& since the slosh is now thicker than if it was just "sloshed" around.

It doesn't really dissolve in MEK, just get loose... and as soon as the MEK evaporates (quickly) it just seems to harden in it's new location.

Lots of MEK is needed - luckily I have a pressure breathing air hood...:D

Wasn't the real problem that the "sloshed in" slosh was coming off in large sheets and clogging the pick-up and gascolator, rather than just dissolving?

gil A
 
My acft tanks were built in 91 or 92. Slosh is not pulling away, dissolving, or flaking. I check the Andair gascolator filter every 50 hours. Not one speck. I have never put anything but 100LL in the tanks. I was wondering if Auto gas or Auto gas with alcohol could cause problems with slosh. Perhaps some of the problems people have been having. Because of that possibility I have not had the courage to try any other fuel. I was thinking if I was going to try Auto fuel in the future I would put an inline filter on each tank before the fuel selector. Then put Auto fuel in only one tank to test it out.
 
The WHITE slosh is alcohol resistance. The YELLOW slosh is not. The WHITE and YELLOW slosh is NOT compatible. Either one will dissolve the other.

IMHO, poor preparation techniques have caused all the fuel tank leaks. SLOSH and PROSEAL do not like to stick to a smooth surface. If the surface was scuffed with a 'scotch brite' pad or sand paper, it has a very good tendency to stick.

My tanks have a coating installed per plans (See Gil's post on brushing) and there are no flakes, leaks, or particles in the filter (gascolator) after over 10-years of flying and 2,075 hobbs hours.

I hope Gil is also using GLOVES with his respirator when he is using MEK to clean out the old slosh.

Randolph Products was the maker of the slosh that we used over 10-years ago. This is a link to what was called out. It appears to be no longer available. http://www.ldrider.ca/techpages/gastanksealer.htm

Here is a link to what is available today but is not what the early plans called for. http://www.aircraftspruce.com/catalog/cspages/sloshcoat.php
 
My first RV-4 had lots of yellow slosh and one tank was completely coated with it almost every square inch where the previous owner tried to chase a leak with it. It started coming loose and floating around in the gas like sea kelp. Major two month project to remove the tanks, clean it all out, reseal with proseal only.

Current plane has just a small amount of white slosh, looks like it was applied very carefully during assembly over the proseal only. I've kept a close eye on it, but not a speck has come off -- plane is ten years old.

As others have mentioned, the yellow is bad, and preparation is key for proseal and slosh. Both of these planes were flown with avgas and auto gas.
 
Scotchbrite

Thanks for the responses.
Can anyone comment on whether or not the procedure to Scotchbrite the inner tank surfaces was something that was commonly known or recommended by Vans? Was this something that most builders did? Seems to be the key... As I have mentioned, this '91 a/c seems to have no peeling slosh.
 
Good gloves

RV6_flyer said:
......
I hope Gil is also using GLOVES with his respirator when he is using MEK to clean out the old slosh.
.....
Click to expand...

Yup ...and using the good ones from the auto paint store that don't dissolve in MEK like the cheap HF ones....:)

gil A
 
777Dave said:
Thanks for the responses.
Can anyone comment on whether or not the procedure to Scotchbrite the inner tank surfaces was something that was commonly known or recommended by Vans? Was this something that most builders did? Seems to be the key... As I have mentioned, this '91 a/c seems to have no peeling slosh.
Click to expand...

My 10/95 (RV6) manual say's to use a stainless steel bristle welder's "toothbrush" for all mating surfaces, that will be pro-sealed. It farther states that some builders etch parts with phospheric acid. This manual is past the time of using slosh & makes no mention of it.

L.Adamson -- RV6A
 
RV6_flyer said:
The WHITE slosh is alcohol resistance. The YELLOW slosh is not. The WHITE and YELLOW slosh is NOT compatible. Either one will dissolve the other.

IMHO, poor preparation techniques have caused all the fuel tank leaks. SLOSH and PROSEAL do not like to stick to a smooth surface. If the surface was scuffed with a 'scotch brite' pad or sand paper, it has a very good tendency to stick.

My tanks have a coating installed per plans (See Gil's post on brushing) and there are no flakes, leaks, or particles in the filter (gascolator) after over 10-years of flying and 2,075 hobbs hours.
QUOTE]
I totally agree with Gary. I believe all of the slosh issues were caused by incorrectly prep ed surfaces or they got contaminated after being prep-ed.

777Dave said:
Thanks for the responses.
Can anyone comment on whether or not the procedure to Scotchbrite the inner tank surfaces was something that was commonly known or recommended by Vans? Was this something that most builders did? Seems to be the key... As I have mentioned, this '91 a/c seems to have no peeling slosh.
Click to expand...

The procedure recommended in the manual was to scuff all mating surfaces. The problem is that if the pour it in and slosh it around method was used (instead of just brushing over the sealed areas as already mentioned) then slosh covers the whole interior of the tank. Even the possibly unscuffed areas. This is where the slosh typically comes loose.

I personally don't think that just because a tank has slosh in it that it must be removed (as Gill is doing). Particularly if it is only on the sealed areas.

One caution that I would provide though...I have heard stories of slosh peeling in large sheets off of smooth skin areas, and being seen waving around in the tank when viewed through fuel filler hole. One of these large pieces could easily block a fuel pickup in the tank. So just monitoring the contents of the gascolator is probably not enough to be safe if you have a tank with the whole interior sloshed and you choose to just monitor it instead of remove it.
Click to expand...
 
Slosh in Tanks

I have read several things on slosh in RV tanks. I built mine in the early 90's. I have not seen a bit of evidence of slosh coming off. No flakes seen in the tank, nothing in the sump drains, nothing in the finger strainers (I've had both sides out), nothing in the gascolator, and nothing in the carburetor filter. Mine was the white Randolph, and brushed over the proseal only. I think much of the issue may come from three possible mechanisms; 1) possible use of ethanol in the fuel, 2) use of other sloshing compounds (there are about four out there) 3). most likely, inadequate prep. In my experience, a solvent wipe is not adequate. Any metal cleaning requires large amounts of water to float contaminants away. I first washed and rinsed with detergent and water. My washing pad was a scotch brite to roughen the surface. The next step was a cleaning with a conversion coating cleaner (Dupont 225S). This is a Phosphoric acid based solution which puts a very fine etch on the surface. Again flood with water per the 225S instructions. I actually called the sealant manufacturer (it wasn't proseal at that time but a similar product) to discuss this method of prep. His response was "oh, that is the best, we just don't put it in our instructions because the chemicals are kind of nasty). True enough - they are so be careful. By the way, if you have ever used conversion coatings (Alodyne, Dupont 226S etc) you will know that the cleaning difference between the prep (225S) and a solvent cleaning is dramatic. Look at the way water sheets on the part.
 
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