Caswell tank prep

Searching for the prep discussion for the Caswell tank treatment and I get information overload! Does anyone have a link to JP's instruction on fb tank preparation for the Caswell Novatech sealer?

Thanks

BC

Just did this with my FB fiberglass Tank. Ignore the instructions where it states good for two gas tanks. For you shall use all of it. Invest in a Home Depot or Lowes 5 gallon paint bucket for the puke that comes out for you will follow the process 4 times.

Take your time. Expect to take a week depending on weather and your environment and don't be in any rush.

If you plan on painting the tank do so afterwards.


Remove and expect to purchase new petcocks. Chances are the cream and whatever else lurks in that tank has destroyed them.

Drain the fuel(I know that's a given). Remove petcocks and replace with bolts of the same thread and diameter. I suggest using a dab of removable silicone thread sealer. Insert these bolts about 1/4 inch up inside the tank(you can see inside the tank with a flash light.)

With the tank level on the ground using wood block or what have you poor 16 oz or Acetone and 16 wood screws into the tank.

Important: you must seal the gas filler properly. I used removable silicone on the metal ring(let dry for about 12 hours), covered by 4 plastic wrap pieces just big enough to cover the hole and then close the flip top cap. Bungi cord the flip top tight.

Methodically swoosh that nasty toxic waste up and down and upside down. Do this for about fifteen minutes.

Removed the bungi cord, flip the tank entirely upside down over the 5 gallon paint paint bucket. You don't want that nasty stuff on the outside of your tank. Pop the flip top open and the plastic wrap along with the Acetone, some of the sheet metal screws, and in my case, 4x4in pieces of cream came oozing/pouring out.

While upside down shake it around for a minute or so then close the gas cap.

Repeat this process 4 times. yes. 4 times. It doesn't matter if you do it back to back. But arms will get really tired.

Once you are confident the tank is void of anything toxic its time to flush the tank with water. 4 times. Fill it up and swoosh it around. You want to make sure all the sheet metal screws make it out.

Let dry, with the bolts still inserted into the petcock holes. Time to dry depends where you are. I used compress air and let sit in the sun for 3 days. Don't leave it out at night.

Time for the Caswell's. Follow the directs precisely. Pour it in the tank and seal it with the plastic wrap under the flip gas tank cover closed. Swirl around for about 10 minutes up and down and upside down. With the tank upright pop the gas tank cover and remove the plastic wrap. You will realize two things. You have some Caswell's left and you may not has sealed all the nooks and crannys. So use the rest of it and follow the same process. There is no draining of any of the Caswell's. You want it all in that tank. It adheres to the inside really well.

With the tank now sealed set it up right, pop the gas filler, remove the silicone bead with an x-acto knife, remove your two petcock bolts. Let dry for it to cure. I let mine cure for three days. A warm garage is a good place.

This stuff works great and, if properly applied, will last a long time.

I hope this helps.

Amend S-S, only detail I might add would be after the last water rinse to chase it with alcohol or accetone to flash off the mositure out of pores even more throughly, with note the accetone dissolves the very resin trying to save. Only about a min of this then toss out. Dry as a bone is just about right to start the pourings. I can take over 20 mins for Caswells to get tacky enough to keep its even layering in place and not sag off. With Caswells it don't matter if a screw or 3 left inside it will just become part of the tank forever more. A ring magnet or on a rod retriver can fish out a screw ya can't bounce out filler rim. Its definitely a labor of love those after us will get to appreciate most. Accetone is what makes brake fluid eat paint and plastic too. good to back up the plastic with towel/rags to absorb most of any spill to don't reach plastic. Ethanol and driving don't mix. hobot

The tank looks original and I don't thinnk there is an agtermarket coati.ng in there. The reason I'm going with the Caswell is a preventative measure in anticipation of the ethanol gas issue.

As such, is the acetone/wood screw treatment still necessary? I used this technique when removing a cream coat in the Triumph tank but if there is no evidence of an additional coating on the fibreglass tank, I think I may do more harm than good.

BC

I think it's still important with regards to "scoring" or to "roughen up" the inner fiberglass surface and give the Caswell the optimal surface on which to adhere. From what I've read, though, the use of acetone is not recommended as it can degrade fiberglass. I prepped my tank with lacquer thinner (and screws) instead of acetone and my original Dunstall tank is still holding up perfectly after 4+ years.

IF there is no added interior-inferior coating then its not necessary to score the surface mechanically but still good idea to chemically etch its inside gel coat with the acetone for a few minutes then evoporated dried by hot air or warm oven for many hours till nill acetone smell. Heat help the Novalac set up faster and harder so highly recommend heating to cure once a single thick [1/8" to 1/4"] or several thinner layers to get similar thickness laid down. This really strengthens tank to crash damage I've found too and if fiberglass eventually wears out from another century of sanding and painting it'lll still be a complete tank of nothing but Novalac epoxy.

Ditto what sole survivor said. My bike is a bitsa with a Fastback tank and I used every bit of the Caswells on it. There was none left over to pour out, not that you can pour much of anything out of the filler neck.
The petcock threads are 1/4 BSP. Plugs with that thread are available here in Oz, Im not sure about the US I think you guys use NPT.
I had intended to smear my paintwork with vaseline before using the acetone but I got ahead of myself and sure enough I damaged it. Oh well a fresh paint job won't be a bad thing.
On the second flush I sealed the filler neck better with some putty and gladwrap, as well using the vaseline. I wanted to see if it would work, even though the damage was already done.
I did notice that some pressure seemed to build up in the tank while using the acetone. Because of that, I didn't put acetone in when doing the screw-shake part. I wanted to shake the thing about as much as my arms would allow without worrying about pressure build-up or acetone leakage. So I did acetone, then wash, then screws, then acetone again, then screws again.
Another variation I made was that I didn't cover the filler neck at all when using the Caswells. It's hard enough to see inside the tank without putting gladwrap over the hole. Nothing came out.
After doing the coating procedure with half the supplied product as suggested in the instructions it was obvious that I would need to use the rest of it. After that I could see a couple of small uncovered spots on the side of the "hump" which I was able to get with a piece of wire dipped in the dregs in the margarine tub. You'd need an endoscope to check the whole tank though.
Cheers
Martin

I have had luck with standard fine thread 1/2-20 bolts in the petcock threads. And I seal the filler neck with a large rubber "cork", available from the home depot etc.

Grease coat will prevent epoxy adhesion. I used wood dowel slowly worked into self thread then greased a bit then run in ~1/4" proud of inside of tap fitting. Too bad gas caps don't seem to seal the best so leaves neck paint at risk.

I wouldn't touch them with a f***'ing bargepole. I phoned them up to supply a sealant for my f/glass tank which they sent, carried out the prep as per the letter, 18 -24 months later all the outer coating had started to lift like big blisters. I phoned them up & the guy said"what colour is the sealant in the tank? I said red, he said you have the wrong stuff, I said i phoned up to say I wanted a f/glass sealant & this is what you sent, he said we would not have supplied this for a f/glass tank! To cut a long story short i got absolutely nowhere with these a***holes & my tank is f****d!

I went to a large hardware store and picked up a rubber tapered plug (1" x 1 1/2") for the filler neck. Worked well for me.

No need to plug the filler hole as there is a lip around inside and pretty easy not to over flow epoxy out even with an over dose put in at once, top side will get plenty of coverage as only sloshed up there while riding not sitting constantly exposed as lower areas. Takes me like 2 cigarettes ~30 min to get set up stiff enough its stays put.

hobot said:

No need to plug the filler hole as there is a lip around inside and pretty easy not to over flow epoxy out even with an over dose put in at once, top side will get plenty of coverage as only sloshed up there while riding not sitting constantly exposed as lower areas. Takes me like 2 cigarettes ~30 min to get set up stiff enough its stays put.

Click to expand...

Added insurance is double layer of saran wrap and a big thick rubberband....this allows the Caswell "slosh" all the way up to the edge of the lip.

Did most my tank rolling while epoxy not at top while still fairly fluid then as it gelled got it to flow like cold honey around filler inside for significant time to assure it filled nooks and left decent layer once tank left upright. But can't be too protective and glad your seal didn't leak. I bet if tank opened and edges beveled and roughed that just Caswells flowing in and setting up would be more than adequate to hold together all by its lonesome. The could back up on outside just for extra emotional security.