In-Wing Kreem Slosh removal method?

[wildirishtime]

I surprisingly can't find any threads detailing exactly the process
used for removing old Kreem from 2000 vintage tanks that are already
in the wing.

The general theory is discussed here and there in various threads, but
no clear procedure is outlined - specifically the threads don't discuss
how MUCH of the Kreem actually comes OUT in the process - all of it in
liquid form (like Kreem says)? or just that which is no longer bonded
perfectly? or just part of it ? Some people say use Acetone (including
Kreem themselves) some say use MEK...

Lastly, what do you guys do after rinsing/removing the Kreem on
the 'old' tanks? Re-slosh with the Caswell epoxy? Or maybe the Hirsch
product? Or is the 'rinse' removal enough if I don't really plan to run
E10 ( I'm a non-eth kinda guy!)?

Thanks!

[egp8111]

I flushed out my mid 90's Kreemed tanks with acetone, poured in about a gallon at a time and shook and rotated the wing everyway I could. At first the acetone drained out cream colored after about three or four times it was pretty clear. I resloshed with the Hersch product sold by ACS. Almost 100 hrs. now so far so good. A general PITA but doable. Enjoy

EG

[wildirishtime]

right, but what did they LOOK like inside when you were done? raw gold colored raw fiberglass? or could you still see traces of the Kreem?

[egp8111]

The tanks still showed some cream color in the weave looking in with a light. When the acetone came out clear I determined all the Kreem that was coming out by that method was out. I suppose you could get more aggressive about what you pour into fiberglass tanks but I wasnt willing to go there so I called it good. I think the big concern is how well the new material you use to re-slosh the tanks will adhere. I'm sure there are a lot of opinions and ideas out there. Like they say your results may vary.

EG

[wildirishtime]

Thanks for the clarification. How's the Hersch product holding up for you now, and are you running E10 over it?

[egp8111]

I'm using local mogas. I regularly check it for alcohol some times it shows none sometimes up to 5% same station, go figure. One of the reasons I chose Hersch product was it is supposedly alcohol proof It's been about 7 months and 100 hrs now since I sloshed the tanks so far no problems

[kitfox5v]

I have two tanks from my '98 kit not installed yet. I have not put the kreem in yet. where can I find the hersch product? I just don't need to buy new from Kitfox if I can treat these so if I get some ethanal by mistake it will not matter. Thanks Eddie

[wildirishtime]

It's available at www.hirschauto.com and other 'fine retailers'.

Anyone else used this or other epoxies on the old tanks AFTER they had Kreem removed? (of course I'm asking regarding bonding strength over the old Kreem residue).

I have a bottle of Kreem in my hand, it says "Advanced Formula-Resists Alcohol" but the guy from Kreem on the phone told me, and I quote, "It's the same formula we've always had". Hmm..... so was it the formula, the fiberglass, mold release, or the application that causes Kreem to release from the fiberglass tanks? This may not be an answerable question.....

EG: Did the Kreem come out in chunks or in liquid form once thinned with Acetone?

[HighWing]

I re-Kreemed my tanks in my first Model IV because of some interesting leaking issues. The leaks were only on the top and resulted in small BB sized blisters under the top coat in the fabric. I rinsed with Acetone as suggested.

A couple of things I can suggest as far as procedure is concerned is to first, tape some plastic over the wing tank area to protect the paint in the case of spills. Second, for some reason, the Acetone rinse seems to produce a gas pressure, so periodic venting will prevent internal pressures from braking a seam. I plugged all access holes with new plugs except the fuel outlet port and put a new hose barb there with a length of hose. I crimped the hose with a spring clamp for the rinsing and unclamped it periodically for venting. For the filler neck, I bought a cap that fit so there would be no Kreem residue on the Pitot cap or gasket.

The hose on the outlet port makes it easy to capture the rinse -or exess Kreem - when it is time to drain the tank. I

I did it twice at the time. The first time by myself with some fixtures I made to make the wing removal a bit easier, but it was more successful the second time with a modified fixture and more help. I would suggest four guys if you don't use a fixture and have people at each end because the tank can get heavy after a while and it is good to be able to keep the rinse going during a rest break.

Another thought - if the wing tip is removable take it off and make some handles that can be slipped into the spars. I used a handle on the inboard end secured with the spar bolts and a fixture on the outboard end. It was made of 2X2 wood wiith holes drilled in them to accept some glued in steel conduit in an H pattern for the handle. PVC would also work for the spar insert part.

I am attaching some photos of my set-up. The final set-up was a bit different. My wing tips were not removable requiring the design. The inner wood support would fold down for manipulation and everything was on casters to move the wing away from the fuselage. The outboard support was a gimbal joint for movement. In the second iteration, I jacked up the opposite wing to lower the tip of the affected wing so the outboard structural support was lower to the ground and it was much easier to slosh without having the inboard guy climb a ladder to get the rinse/Kreem on the outboard tank surface.

Definitely not a fun job, but doable and the re-Kreem worked perfectly.
Lowell

[egp8111]

Mine came out as a liquid. Seems the acetone dissolves it pretty quickly.