Caswell tank sealer

[rf9rider]

Hello all. been a while.

Before i get my tank resprayed, thinking of doing the tank with the Caswell sealer, though i can`t find any info on prepping the inside, anyone who`s done it offer any advice?

[beezerboy]

well......... I've done a few. if there is old gas & varnish, that has to go. slosh with more gas, alcohol, acetone... whatever it takes to remove it all. then, if there is loose, flakey rust, that needs to be removed too. there are a number of ways to mechanically remove this stuff. like nuts & bolts, BBs, etc. the idea is you drop them in the tank and rattle them around to dislodge the rust.  I've got a piece of chain with small links and put a screw through each link with a nut (when you are all done it comes out easy).  next step is to neutralize the remaining rust. most "conversion coats" made to do this are primarily phosphoric acid. stuff like naval jelly, Ospho, Alodyne, MetalPrep and other brand names. the phospho converts the remaining rust into a phosphate which is basically inert. then that is water rinsed and dried thoroughly, then its ready for the coating.

some sealers like POR15 don't care if there is rust left... they bond to the rust. this a sealer I have used with good success at least half a dozen times.  I haven't used Caswells sealer but I have some of their plating stuff... it works ok.


actually.... heres from Caswell (Methylene Chloride is the active ingredient in paint stripper... the crap that burns your hands, etc)     

Application Instructions

All traces of oil and gasoline should first be removed by pouring about 1 pint of acetone or lacquer thinner into the tank, and rotating the tank several times to thoroughly sluice the sides with solvent. Dispose of the contaminated solution.

When recoating your gas tank from failed Kreem or POR-15 tank sealers, remove the old, failed coating using a paint stripper containing Methylene Chloride.

Place a hand full of drywall screws into the tank and shake them around vigorously for several minutes. These will dislodge any loose particles of rust. In the case of Fiberglass and plastic tanks, this will rough up the tank interior, improving adhesion.

Rinse out the tank with about 1-pint of acetone or lacquer thinner, then set aside and allow to dry. Use an airline to blow air into the tank to aid drying.

Apply duct tape or masking tape to any weeping seams, holes or porous areas. This will stop any Gas Tank Sealer from oozing out, and will allow it to bridge over the hole. Plug the outlet ports with putty or Play-Doh. Mix up the required amount of Gas Tank Sealer (one unit should treat two small motorcycle tanks or one large one) If you are only treating ONE small tank, then divide parts A & B in half. You could use a dipstick to gauge this.

In a separate plastic container (margarine tub etc.) mix the two parts together thoroughly for at least 2 minutes. Scrape around the sides to ensure all resin is blended together. BAD MIXING AND BAD MEASURING IS THE #1 CAUSE OF FAILURE!!

Pour into the tank, then immediately seal up the filler hole with Gladwrap and an elastic band. Swill the tank around in every direction for several minutes to obtain a good layer of Gas Tank Sealer over all surfaces. Remove the filler cap,Gladwrap seal, and pour out any excess. Allow to drain upside down for a few minutes.
If you have a built in fuel filter, blow air into the fuel line port for about 10 minutes. This will clear the filter of any Gas Tank Sealer.

Scrape off any excess with a sharp knife at this point (usually about 40-60 Min after mixing) Place the tank in a warm 70-90 f place and allow to cure overnight. In the case of alcohol fuels, allow 3-5 days at room temperature, or 24 hours at 120 deg f.

[ssevy]

I have sealed both my metal Legend fuel tank and my nylon Tiger fuel tank with the Caswell kit, and both have had no issues since. For a steel tank, the Caswell works great, as you are preventing any possibility of future rust developing. In fact, if I ever bought a brand new bike that had a steel tank, I would seal it with a Caswell kit immediately, and eliminate all of the potential headaches from the damned ethanol in our gas.
Our nylon tanks, on the other hand, don't have the rust issues, but the Caswell kit will also prevent our ethanol issue, which is tank deformation. So, I am assuming that this is the issue you are addressing, and if so, then my advice about letting the tank air out for a long period is going to be your most important step in a good preparation.

Again, since your tank is made of nylon, it may have some sludge or other sediment in it, but the inside surface cannot rust. All of the suggested scrubbing of the inside of the tank with screws or chains or solvents isn't necessary. I would not use any strong chemicals on your nylon tank, as they may deform it.

Here's what I did:
1- with the tank off the bike, slosh some clean gasoline around inside and then pour it out into a clean jar. Do this several times until no sediment or other junk is present in the fuel you are pouring into the jar.
2- carefully remove the filler hardware and the petcock, and then fashion some cork stoppers to plug their holes. You can put some saran wrap or other plastic over the plugs so they are easily removed once the kit cures.
3- my tank needed some welding with a nylon rod, as my petcock mounting inserts were shot. The waiting period to have this done let my tank air dry for several weeks, and during this time, all of the deforming caused by ethanol over the years disappeared, and the tank returned to its original size and shape. Therefore, I would recommend that you let your tank air out in a low humidity environment for at least two weeks before you seal the inside to achieve a stable dimension for the sealer (Caswell told me the sealer has some "give" to it, but if you start with an expanded tank and then it shrinks with the sealer in place, you may be exceeding the sealer's expansion or contraction limit).
4- you'll need a disposable plastic dish for mixing up the sealer, and a plastic funnel for pouring it into your tank. Having done this for my Legend, I then flexed the plastic dish coated with the leftover sealer, and it stayed in place just fine, another reason I had confidence that this would work well with our nylon tanks.
5- I used a roll of that stretchable plastic wrap that is used for shipping stuff to completely wrap up the outside of my tank to keep it from getting any sealer dripping on the outside. Then I mixed up the sealer kit and poured it into the tank, having sealed the holes in the bottom with plugs. Once the whole bowl was in the tank, I plugged the filler hole and then sat in a chair, turning the tank every conceivable direction to let the sealer thoroughly coat the inside. This took about 15 minutes or more, and when I was confident that I had coated everything, I removed the top plug and poured out the excess sealer back into my bowl.
6- let it sit in a normal upright position to dry. Once the leftover sealer in your plastic dish is getting pretty stiff, you may want to remove the bottom plugs, and if necessary use a sharp exacto knife to trim any sealer that may be blocking the petcock drain hole. A sunny day with low humidity is a perfect day to do this project, and I would let the tank sit outside in the sun while it cures.
7- Be careful not to over tighten the hardware when you reinstall it, as those brass inserts like to spin and then you have a bigger headache!
8- Here's the article I wrote for webbikeworld when I did my Legend tank for reference:  http://www.webbikeworld.com/t2/caswell-fuel-tank-sealer/

[rf9rider]

Cheers Sevvy, a lot of useful info there.

Looks like a job for the summer.

[Danwarb]

Brilliant thread this . . . I've got a spare tank where I'm about to glue back in place the removed 'spinning tank nuts'. Once I've done this I'll likely take this on.

Thanks guys.

[threepot]

Brilliant thread this . . . I've got a spare tank where I'm about to glue back in place the removed 'spinning tank nuts'. Once I've done this I'll likely take this on.

Thanks guys.

When I bought my bike,it had a leak from one of the tank nuts. I fixed it with  a 2pack adhesive product that was labelled as oil and petrol resistant. 'Wilko' branded? Did the job,and has lasted 5yrs.

[Danwarb]

When I bought my bike,it had a leak from one of the tank nuts. I fixed it with  a 2pack adhesive product that was labelled as oil and petrol resistant. 'Wilko' branded? Did the job,and has lasted 5yrs.

I was going to use the plastic version of JB Weld. Which do you think is better? This or the Wilko?

[threepot]

Sorry,never used JB? I checked the Wilko site. Couldn't see the product I used. What about this?..
http://eclecticproducts.com/seal-all.html

Available on eBay/Amazon

[JayDub]

I was going to use the plastic version of JB Weld. Which do you think is better? This or the Wilko?

Bear in mind that your tank is Nylon, not plastic.  I used JB Marine weld for mine, good stuff... its fuel resistant.

[Danwarb]

Bear in mind that your tank is Nylon, not plastic.  I used JB Marine weld for mine, good stuff... its fuel resistant.

JB Marine Weld ! Thanks JayDub

[bemusedinsojo]

I did my Steamer tank in December when the temps were below 20F. Follow ssevy's warning and let the tank sit empty for some days so it will go back to original size.
I plugged my petcock holes etc with play doh and silly putty which I wrapped with plastic wrap before I inserted it into the various holes (the plastic wrap keeps the play doh from falling apart while in the tank).The directions say to use warm water and Dawn dish soap to clean the tank, which I used. Then dump drywall screws in the fill hole. Slosh the tank around with the screws, which will roughen up the surface so the Caswell will adhere. I advise to only fill the tank half full of water so the screws can get some good movement while sloshing. I did this twice because the inside still smelled like gas. The second time it still smelled like but I drained and let the tank dry in the bathtub for three days (my wife derided me for that one).

Mix the whole batch of Caswell you get-trying to mix partial batches may result in improper measurements which may result in a bad batch, which will not stick to the tank, which will stress the one who is coating out. When mixed, the coating has the consistency and look of honey. The Caswell directions say to hurry hurry hurry and coat it before it dries. I found that it didn't dry too fast, that I had plenty of time to swirl and rotate the tank in as many ways as possible. I think it helped me to visualize there I wanted the coating to go in the tank so all surfaces would get coated.

After I was through with spinning the tank I removed the petcock plug to drain out the excess which wasn't much. Then it went on an old cardboard box on the floor in the upstairs bedroom (much to my wife's chagrin) to dry. I put a space heater next to the tank to bring the room temp up to about 80f and kept it in there for three days, rotating it every so often as it dries. When it is dry, cut away any excess that will interfere with the operation of petcock etc. Inside you will see a shiny, honey colored coating in the tank.

Oh yeah, don't forget to remove all your silly putty/play doh plugs and throw away. They will smell like gas so not a good idea to give to the kids to play with.

Then install and fill with gas. I just filled my tank for the first time three weeks ago so I have no data as to the longevity of the seal but so far so good.