In checking a couple KD3S or WD3S cast tanks one of them passed the breath
test and the other failed...so I am going to see how my luck holds in splitting tank halves and resealing with new gasket. One requirement is
warm weather as the contact cement is too potent to use inside...solvent vapors overwhelming. I have done this before with a WD4S tank with
excellent results. Last Winter had some nice days so maybe sooner than
next Spring. If anyone else has a leaky cast tank maybe worth a question
or two. One thing for sure...If I can do it, it ain't rocket science.
I haven't been able to try it yet, but a tube of super glue squirted in and rolled around the seam might be an alternative to splitting the tank. It works well on coating waterlogged cork floats and is impervious to gasoline. I just wonder how much prep it would take to get the oily gas out first to get a good seal.
Replacement of one tank gasket does not an expert make.
Tank in question was a "can't hurt, might help" situation...
a lot of gasket was gone...leaked like a sieve
stud thread corroded away to point nut would not hold.
Having nothing to lose I went to work and found the project was pretty
straight forward. Making a replacement stud did not go smoothly, but,
after relearning some lessons that worked out as well.
Careful checking using a machinist's straight edge revealed gasket flanges
on tank were remarkably flat. Other than straight edge and dies no
special tools needed.
That was a tank for a twin. Now I have a tank for a single with a leaky seam
...the fact that I have left over gasket stock and Seal All may influence my
approach to a solution. If you have a hammer everything looks like a nail.
You are correct to point out need to clean. Strong solution of Super Clean
will handle oil,grease and gas residue...sludge would tax lacquer thinner
to liquify and remove...nasty stuff. Gasket surfaces need to be clean down to
bare metal..old gasket & glue take single edge razor blades and careful
effort...wipe down with lacquer thinner prior to applying
Seal All...maybe overkill...leave nothing to chance and chances are
nothing will go wrong.
Today does not look favorable for outside work...falling temperatures
with light snow overnight...some accumulation possible...weather forcaster's
Fumes from lacquer thinner and Seal All are so strong they should not be
applied inside...much stronger than gasoline! Seal All is a contact cement
that works by solvent evaporation...works best when warm and takes several
hours to set up after tacky surfaces are joined...either Spring or an
unseasonable warm spell required.
I was reading the literature for Seal All and it says that it is a thin product. It says that it doesn't stick to paper but based on your experience there is no problem with gasket material. Any particular type of gasket that you used?
Fel-Pro Karropak tan fibre sheet part No 3046 which happened to
be on shelf next to Seal All...generous size (36"x12"x 1/32") sufficient to
seal two tanks plus enough left overs to make gaskets for one
or two motors. Karropak is a general purpose gasket material resistant
to oil,coolant and gasoline NOT exhaust heat. Seal All is not affected by gasoline,oil,alcohol or water and can be used as sealant or contact cement...
seens suitable for this application. I did not read that it would not stick
to paper.Seal All has about the consistancy of catsup or mustard...not like
water or peanut butter.
When I took tank halves apart I had to clean remains of gasket off tankd
flanges that peeled and crumbled as well as adhesive that had to be razored
off with a single edge blade.
With the fasteners tighted down and sealant set up tank assembly passed the breath test...no leak when I held finger over outlet and pressed mouth to tank fill opening and applied lung power...I think good to go.
Thanks for the response Louis
Outside tempertures will be in hi 50's Monday so I got busy today cleaned up
flanges of KD3/WD3 tank top and bottom halves. Used machinist's straight edge to check if tank outer flanges were flat and even. They proved to be reasonably flat...the inner circle flang seemed a little low but within a reasonable tolerance. Anyway tank will be sealed and joined if weather holds
and a higher priority does not come up.
Taking lots of pictures to show everything step by step. Also to show
technique (simple clamp)that will take place of heavy weight used with KD4/WD4 tank and a little refinement to ensure contact cement sets up
Need to work on how to post photos...my bad.
Hi Louis. I used your process to seal my first 2 piece cast tank today. It was nice to split tank, and really clean the tank good. That Seal All is sticky, and keeps the bugs away Thanks for posting your method. I'll let it dry until I have time to work on my Sea King K1.
Good to hear that written comments are clear enough that you can
use them as a guide. Got going on sealing tank today, but did not get
tank joined. Need to go get some more Seal All...one tube is not quite enough to do two tanks. Took pictures of process that somehow will have to be shared. Leaking seams on cast aluminum tanks are fairly
easy fixes...other than a 3/16" hex key, 1/4 x 20tpi and 1/4 x 28tpi taps & dies and an Exacto type knife with sharp blade no special tools needed.
One thing I may not have mentioned is when trimming out gasket with Exacto
knife is to cut on DOWN stroke...cutting on upstroke may drag the gasket
away from flange which may tear it or impair seal.
My way may not be the best way but it is the best way I know.
Your way may be better and someone else's way even better.
The best way may involves a combination of elements from each.
Worked on sealing and joining tank today even though temperature was probably
on cool side for Seal All to set up...a couple thoughts that may help with your tank work...
1) install long studs to rear and short studs to front...as I was getting ready to install fasteners I noticed studs were not in proper holes...compared with another tank to confirm I had it wrong...easy enough
to fix but my face is red...
2)I tighten fasteners as follows 1st short studs around flywheel 2nd the long studs (using long nuts) lastly the socket head screws at ends...I do not
know if this is factory way but it seems reasonable.
All fasteners should be fairly snug but don't go so far as to strip out threads in aluminum tank.
If you are removing or installing a tank do not
disturb the fasteners holding tank together as that may relax grip on
gasket/sealer which may then leak...especially on an original tank seal.
3) As I was considering how well Seal All would set up in cold I happened to notice an aluminum flood lamp (the kind with a holding clamp you see at HF)...a real light bulb moment! Pluged in lamp, turned it on and set it over the flywheel opening of tank and left it for an hour or so...upon my return tank was warm to touch all over and fumes abated...tank passed the breath test...so I guess it is good to go.
Now that I have split and resealed a KD4/WD4 twin tank and a KD3/WD3 single
tank it appears to be a fairly simple to do project. Not a lot of time or special tools needed.
There has been discussion about warped tank halves...those might be a toughie. Replacement postwar cast aluminum tanks are available and reasonable
unlike some of the prewar Models.
Wizard WF4 and WG4 have a more complex cast aluminum tank. I don't know
how easy or difficult they might be to reseal...some time ago I had one
that had been "gooped" with something black in an attempt to stop a leak... scrapped it out...today it might be worth splitting open and resealing.
As always my methods and views are my own. You are welcome to follow,modify
or ignore as you choose.
Ok. I just did another tank today on my KB1. Somebody had soldered inner ring in the past, but it leaked horribly. Luckily the solder scraped away easily. I learned a few things on the first tank I did. I'm not an expert, but figured I pass along my experience. After cleaning and prepping the tank, I took the bottom half (without the studs) and applied a coat of sealer to mating surface. Then I spread out material on clean workbench, and carefully set down tank half. After sealer was dry, I was ready to trim down material. Using a heavy duty paint stir stick (sturdy one), I colored one end of stick with a pencil. You then rub the colored end of the stick over the gasket material. You may have to color a few times. It will leave a good line for trimming the gasket. Just trimmed the excess first, then came back to fine tune the inside edges of the tank (the outter edge and inner ring can be done after tank is assembled) I then drilled out holes in the gaskets where bolts pass through. While upper tank studs are accesible, go ahead and run a die over threads. Next apply sealer to upper half of tank, and reassemble. Tighten bolts up to pull tank together. After tank is dry, take a sharp razor knife to trim off excess flush to end of tank (being careful not to dig into aluminum). After all of that was done, I ran a thin coat of sealer around edges of gasket. I just want to make sure all areas are sealed well. Then after dry a light sanding to nock down high spots on sealer.
I mounted the gasket and bottom tank half to a piece of plywood and used
a nut, washers and bolt to clamp tank down on gasket.When Seal All
sets up I trim gasket away from outside edge of tank and cut circle of
gasket out then flip tank over and cut gasket away from flanges of
outside edge and inner circle...Sharp blade required.
One thing I think is important is to apply Seal All to both tankd flanges
and to gasket stock then wait until it is tacky before clamping tank to
gasket or to assemble tank. Per instructions Seal All cures by solvent
evaporation...so I wait until tacky. Probably not vital but seems like
a good practice.