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View Full Version : In-Wing Kreem Slosh removal method?



wildirishtime
11-15-2012, 02:53 PM
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
11-15-2012, 03:23 PM
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
11-15-2012, 03:29 PM
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
11-15-2012, 04:04 PM
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
11-15-2012, 04:06 PM
Thanks for the clarification. How's the Hersch product holding up for you now, and are you running E10 over it?

egp8111
11-16-2012, 05:10 AM
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
11-16-2012, 07:44 AM
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
11-16-2012, 09:42 AM
It's available at www.hirschauto.com (http://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
11-16-2012, 10:02 AM
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
11-16-2012, 10:08 AM
Mine came out as a liquid. Seems the acetone dissolves it pretty quickly.

wildirishtime
11-16-2012, 11:37 AM
Heck of a super structure you built there, thanks for the photos and the details, it 'fills' the gaps that the other threads weren't covering.

napierm
11-21-2012, 08:03 PM
I did one wing on my KF III. I use some spray masking liquid to help protect the paint. To rotate the wing, I used a long 2x4 jury rigged with foam, rope and tape. Then a rope and pulley attached to the end of the 2x4 helped to lift and rotate the end of the wing (and helping hands) while rinsing and then sloshing. BTW, Kreem is available stand alone w/o the "kit" which you don't need.

Best of luck,

Mark

Spook712
05-02-2013, 02:36 PM
Hello, I have kind of the same problem, the old Kreem is coming appart in the tank which is installed in the wing.
So how did you shake and turn the wing to get it out, or would it be easier to take the tank out of the wing cutting the fabric open.

How is the Hersh product called exactely, I can't find it on the internet and why is it better than Kreem ?

Thanks for the help,

Tuna

egp8111
05-02-2013, 04:24 PM
You have to take the wing off. A couple of guys can shake and rotate the wing with acetone in it. Do it until the acetone comes out pretty clear. AC Spruce sells the Hirsch(sp?) slosh. No need for cutting

Wingnuts
05-02-2013, 04:29 PM
Has anyone used the Caswell product?

Av8r_Sed
05-02-2013, 08:40 PM
The product name is "Alcohol Resistant Gas Tank Sealer"

http://www.hirschauto.com/prodinfo.asp?number=GTS

Spook712
05-12-2013, 01:13 PM
How much did you use for one 13 Gal tank?
Is one quart enough per tank?

egp8111
05-12-2013, 05:53 PM
A quart was enough to do a 13 gal tank a couple of times. Get a strong buddy to help you really move the wing around with the sealer in it. I got a short piece of NPT threated pipe at the hardware store to screw into the fuel port. It made it easier to drain out the excess.
-EG

Spook712
05-14-2013, 09:28 AM
So I bought 2 quarts hoping its enough !

Can anyone send me the application instructions by mail.
The only info i found was the sheet on the homepage.

Thanks
Marc