Trying Caswell Gas Tank Sealer on a Rusty Motorcycle Tank-1953 NSU Max Restoration

In this one, I seal up the old NSU Max motorcycle fuel tank with some Caswell Fuel Tank Sealer after welding a broken tank pad mount. Caswell comes in a nice red, Dragon's Blood red as they call it. The tank liner turns out great and I learn some things in the process. Hopefully you'll learn some stuff too. I hope you enjoy.

[@bridgeman11]

Robert is very thorough. I had a tank with rust. I cleaned it with a lot of pointy screws and shook it for a long time. Then I rinsed it and soaked it with a phosphoric acid solution for 24 hours. It got pretty clean and exposed a lot of pinholes on the top of the tunnel, probably the thinnest part of the pressed bottom. So I put some duct tape on the bottom of the tunnel (outside) to contain the epoxy. Did the rest of it like Robert shows. After hardening, I removed the tape. It worked well. This stuff cures hard as a rock! I'll use it again on similar tanks.

[@KB-uu4fy]

I have done three tanks with this stuff now. It is excellent. I did a Harley FXDL tank two years ago, which was full of rust. It still looks great inside after two years. It is all in the prep though, and allowing loads of time between each process. Ŷou cannot rush it. Great video

[@tanveerahmad5846]

I wash fuel tank with acid but after washing with water it's get rust how to prevent from rust can I apply pro 15 on it and how you wash fuel tank gave me tips, How much pro 15ml used in 12.5 fuel tank ?

[@JagLite]

Great video! It helps to show that things don't always go the way we plan but we can often save it. I've used Caswell Tank Sealer in three motorcycle gas tanks (so far) and all have worked perfectly. The oldest one is a fiberglass Rickman Metisse tank that is 10 years old. (I don't drain the gas out). I've also used it in my 82 year old Matchless steel fuel tank. I did a lot of research before using it the first time and Caswell had the most positive results by far and the few less than perfect results the user admitted not following the instructions correctly. I recommend Caswell to everyone and tell them to just follow the instructions.

[@captlarry-3525]

I am going to buy some clear flexible 2 part epoxy ( west marine or home depot) in 8 or 16 oz bottles ( about $33) I will mix and dilute with acetone... until it is liquid enough to coat and drain from a 2 gal generator tank. The tank is sound, I will prep well with diluted phosphoric acid ( hdepot metal etch) neutralize the tank inside with baking soda and water, rinse well and dry on a heater or in sun.. then coat. If it is still good in a year... we've got a winner.

[@LewisAraujo]

Your advices have been of full help. Tks

[@bake162]

I used it on my Laverda about 17 years ago and it’s holding up just fine

[@captlarry-3525]

1. Prep is everything. You did that pretty well. I use cleaned sharp gravel, and diluted phosphoric acid, and shake the shit out of it. Remember the top of the tank is where the condensation of water happens... so it rusts too. 2. I have always used 3M EC-776 it is an industrial product ( aircraft mostly) probably hard to get and expensive. it leaves a clear red coating that looks like original BMW...and I have never had it fail. 3. Time Tells The Tale - because the new fuel is loaded with ethanol many commercial tank coatings that used to work fine.. are now failing in less than a year. Of course many guys will NOT prep properly, or at all ! The 3m product is an engineered Urethane coating, in a high volatility carrier ( something akin to MEK) They have two versions. The SR does not use Ethanol as a solvent... I would check 3m literature or sales rep for more info.

[@skyfreakwi]

If you hook up a shop vac onto the fuel filler right after filling it will pop the bubbles. It will also probably coat evener if you slowly roll the puddle around to coat all the surfaces. Shaking will make more bubbles and not lead to even coating. It's just to viscous.

[@RobertAdairWorkshop]

I'm going to use the same stuff on another tank. That's good advice. I'll use it. Thanks!

[@skyfreakwi]

@@RobertAdairWorkshop no problem. Also when you mix it try to just use a circular motion with your spatula. If you try to pull the bottom up to the top it will make more of a whipping motion and create a lot of bubbles. Good luck, I hope to see the video soon. Also how's the B&S #2 grinder coming along? I just watched a new video and it looked like you were cranking it manually. Is there an issue with the power feeds?

[@RobertAdairWorkshop]

@@skyfreakwi I need to recondition the motor and fit a belt. The X direction feed should work but the Y is missing the drive mechanism. So half automatic if the motor works.

[@Jeff82556]

At 03:49 I was surprised you poured out the contents from that height! That just invites air bubbles. Most guys would slightly tilt the white plastic bucket and gently pour it down the side to minimize air bubbles - not from 6ft up in the air! (okay, so I exaggerated a bit)

[@RobertAdairWorkshop]

I did get some air bubbles. Wasn't even paying attention to how high I poured it from. It's good to note.

[@philliphall5198]

Thank You for information and advice Merry Christmas 😊

[@captlarry-3525]

Use the threads in the pet cock outlet to hold your plug...twist it in, untill it wont turn any more.. I use wood.

[@Arizonahwy10]

Did it seal the pin holes?

[@RobertAdairWorkshop]

It did, yeah. No leaks, no failures, so far.

[@Copyright-di4we]

Is that just epoxy resin?

[@RobertAdairWorkshop]

It's an epoxy resin but not regular stuff. This one is fuel and ethanol resistant. Caswell says it is "Phenol Novolac Epoxy".

[@JagLite]

@@RobertAdairWorkshop Yes, Novalak is not the typical epoxy resin. It is excellent for fuel tanks, especially if using Ethanol mix gas.

[@carlodangelo8348]

caswells ? this stuff is unobtainable ..the 2 part

[@ambrechambers7094]

​@@carlodangelo8348I've been checking online and everyone is out. Even Caswell is out.

[@papertrail44]

@@carlodangelo8348 UPS just delivered my "unobtainable" 2 part Caswell tank sealer.

[@captlarry-3525]

1. plug your petcock hole after removing it. 2. you must protect the outer tank...you cant remove the stuff. 3. you only need 1/4 of the stuff you have just mixed and wasted. remove masking after draining it all out

[@BIBIWCICC]

Doesn’t work with fuels containing small amounts of ethanol. I have two tanks to prove it.

[@RobertAdairWorkshop]

That’s unfortunate. We have 10% ethanol in the gas here, I think.