[Master Designs]

I'm investigating the option of disassembling my 1st generation (forward facing baffle) sloshed -4 tanks using something to strip the exterior paint and primer, then drilling out all the rivets and using something to remove the pro seal and slosh, and then re-assemble the tanks using the clean pre-drilled parts...new pro seal, fittings, sending units, etc...

Is there an aluminum safe chemical that could do everything: strip the paint, primer, pro-seal and slosh? It doesn't have to be all one chemical, but it would make it nice. I'd also like to stay away from the super toxic stuff like MEK if at all possible. Thoughts?

 

[t4tango]

Pro seal Remover

Coincidentally, I have just had the pleasure (!) removing the tanks and the access plates on my -4 to renew the sensors that had packed up some time ago. As I wasn't the original builder, I had to proceed with caution removing all the parts however I found that I needed to use a combination of chemical ( Poly-Gone from Vans and some acetate, used my wife's nail varnish remover!) and mechanical ( very careful use of Dremel cutting wheel and wire brush to break down the poly seal ) and it took a long time using sequences of both methods. Eventually the plates were very gently removed and I have spent the time since cleaning them all off and preparing to install the new float type sender units. The tanks are all back together now using the 'black death' type tank sealant from Vans and curing away gently in my garage. If I had to do it again, I was left wondering whether it might have been easier to build two new tanks...........

 

[Vern]

Tank Sealant

Skip the quart cans of Pro seal and buy it in the tubes. It is similar to painter's caulk and even is mixed inside the tube. Spruce and others sell it. They also sell the 'gun' to apply it with.

There are also some clear colored devices that look like a small turbine wheels to fit on your drill motor to help remove the stuff. I use a 3" wire wheel chucked into an air drill to remove old fillets and prep metal parts for cleaning with MEK prior to re-applying the proseal.

 

[Master Designs]

I'd like to find something that I can pour into the tanks and slosh (I'm not a fan of that word right now ) the chemical around to loosen up and remove a good majority of the proseal and slosh. I know most builders want a chemical that removes one but not the other...I want something that removes EVERYTHING but the aluminum.

If I had to do it again, I was left wondering whether it might have been easier to build two new tanks...........

I'm with you t4tango....I've been trying to decide if I clean up my tanks, build new tanks (I don't really have the time to completely build new tanks) or have Evans build me a set of new tanks. I'm trying to decide on the best solution, and figured I'd investigate a clean/re-build of my tanks before I fork over the money to buy new tank parts/ribs/skins from Vans (approx. ~$900.00).

Since everyone likes photos.....here's a couple of photos of the interior of my tanks. The photos were shot through the side inspection panel. The color of my slosh is tan, and doesn't cover every square inch inside the tanks. Lots of it looks painted on....maybe before the last baffle is put on?

 

[penguin]

I've just had to do a small tank repair - MEK is about the only stuff that will dissolve Pro-seal, and even then at a fairly slow rate with plenty of rubbing.

Gas is a good solvent so anything that resists it (ie Pro-seal) will be tough to remove. Use 2 x nitrile gloves and be prepared to change regularly, plus a mask/respirator.

The Bristle Discs to help remove Pro-seal are available from Avery, 3" dia for $9.50, #30098

Wouldn't it be easier to build a new tank from scratch?

Pete

 

[Master Designs]

Wouldn't it be easier to build a new tank from scratch?

If I can drill out all the rivets and the parts come apart fairly easy so I can quickly clean them up and reassemble.....then that would be the easiest.

However, if they are prosealed together like crazy.....then you are correct.....building new tanks will be easier and that is what I will have Evans do.

Figured I'd spend a few hours to see how well these are prosealed together before I buy/build new tanks. Won't cost me anything to do some investigating.

 

[rzbill]

Take a look at these.
I have never used them but I understand they are used for jobs like you propose.

Avery Sealant Cutters

I have used MEK and Naptha Laquer Thinner (my preferrence) to dissolve Proseal but I don't know how either would work on very old proseal. As stated previously, neither work quickly.

 

[Andrew M]

Proseal rework

How I cope with this issue professionally is: drill the heads off. Using a heat gun and some old butter knives, gently wedge apart, pry apart the assemblies. About the butter knives, grind them to a sharp edge favoring neither side (a chisel favors one side), and round the corners. The blade is a little thicker than a scraper and helps to separate the parts as it cuts the sealant. Any marks left on the metal should polish out by hand with scotch brite, as long as the corners are round. When using the heat gun, don't wear gloves. There is a caution in AC43.13 about heating aluminum past 212 degrees. Working without gloves will keep you from getting to hot. Once everything is apart, try grabbing the tails with a pair of flush cut pliers, drill, or punch while suppoting the back side. I remove proseal mechanically, with very sharp small wood carving tools with the corners rounded, and scotch brite by hand. If some small amounts of sealant won't come off, and it is not in the way of reassembly, I leave it.
Sounds like a chore, good luck.

 

[BillL]

In the last thread asking about proseal/slosh removal I suggested methylene chloride. It is not flammable but is volatile and should not be inhaled. It is about $20/gal and if you get it, keep a layer of water on top to keep it from evaporating. Read the MSDS before you use it.

Check the paint removers at the hardware - the best have that as the active ingredient. That will tell you if it works.

Be careful ! the last time I suggested this stuff, it killed the thread!

 

[Master Designs]

Sounds like a chore, good luck.

Geez Andrew.....could you post something a bit more uplifting? Just kidding......great post.....lots of awesome tips. I'm starting to think this task might be a 1 out of 10 on the fun meter, so I'll investigate my tanks a bit more on how well of a proseal job the builder did and then probably order my new tanks from Evans.

 

[walkman]

How is carbon tetra chloride?

I just found out my dad has a 2 gallon drum of it along with about the same of trichloroethane.

 

[skylor]

Poly Gone

I second the Poly Gone product than Vans and Spruce sells. It really works, and since it's a jelly it will stay where you need it to. On thick areas, use it a little at a time and scrape the softened pro seal off in layers with a plastic putty knife.

Skylor
RV-8
N808SJ,Flying

 

[Keith Williams]

One More Slosh Data Point (sorta long)

I built my RV6 tanks in 1991 using the recommended method of roughing up the surfaces under the ribs, applying pro seal and brushing white slosh over the reachable prosealed seams before applying the back plate. Then prosealed and riveted on the back plate followed by a cup or so of slosh that was truly sloshed over the inner backplate.

Finished the plane in 1999 and after a couple of years noticed some slosh hanging loose inside, near the filler opening. Reached in and broke off piece. It was hard, postage stamp size. I have been flying the plane that way for these 14 years and because I have never found any slosh in a screen, gasculator or sump check have just lived with it.

This year, I decided to do the service bulletins in that area and check the slosh issue. Over the last couple of weeks I opened up the rear of both tanks. On the left tank, where I had seen the loose piece, ALL the slosh was tight except that little place I had seen earlier. On the right tank, where no loose slosh was visible, almost NONE of the slosh was tight on the back plate. The hole saw produced a nice aluminum disk (no slosh on either side) plus a nice white disk of hardened slosh. Same story in the other five bays. So much for process control procedures at this homebuilder "factory".

With access to check all the slosh I found it all firmly in place except for the right tank back plate. And boy, is it firmly adhered where it was properly applied. Then I spent some time reading VAF "slosh" threads. I found a lot about slosh removal and a lot of concern about slosh but no instances of slosh actually causing a problem. Talked to some folks around the Van's tent at OSH. Lots of concern but no one recalled loose slosh actually causing a fuel stoppage in an RV.

Because I am so impressed by how well the slosh stuck where it was properly applied, and because of concern about doing more harm than good (to me and my tanks) by going at it with chemicals, I decided to carefully remove the remaining loose slosh, seal the adjoining edges with proseal, close up my tanks and go back to flying and checking.

One more comment - this whole exercise was much easier than I had feared. Tanks came off easily, hole saw made quick work of access, closure plates from Van's worked well and the balloon stayed up this afternoon. After having checked it, I am comfortable with the slosh in there. If I sell the plane the buyer will know about it and can go forward from there.

Just a data point - not a recommendation for anyone.