LEAKY Tank - Help Needed

thefish

Been Around the Block
Got my first project - 1983 Kawasaki 750 LTD. It's sweet and I love the potential. Only 2,200 miles and has been garage kept. One big problem now - the tank may have a leak in it. Okay, I'm waiting to see the results from placing a rag under the suspicious spot. But it doesn't look good.

Not sure if that is something that can be sealed up? It's got a fair amount of rust inside the tank as is but that could be cleaned out. Does anybody have a spare tank from the 80's lying around? But seriously ha...ha

Or can anybody please point me in the right direction?

Thanks!

Pics will be uploaded as soon as I'm not on my work computer
 
POR15 tank sealer kit (for motorcycles) comes with everything you need to clean and prep for the sealer and FOLLOW THE INSTRUCTIONS
 
So sealing it is an option? I've heard it's best not to. But the tank is pretty much brand new so that'd be ideal.
 
Kamn said:
POR15 tank sealer kit (for motorcycles) comes with everything you need to clean and prep for the sealer and FOLLOW THE INSTRUCTIONS

It seems to me that this would simply put a coating overtop where rust used to be. But if there's a leak then there is a hole. Would it patch this up?
 
You need to remove the rust and prep before you seal. Like Kamn said, follow their instructions and the kit comes with a de-rusting agent, If the hole is a smal pinhole, a sealer should fix it just fine. If your tank has turned into swiss cheese (see my XL350 thread) you will need to have it welded up.
 
I don't think POR15 is actually intended to seal pinholes or any other structural deficiency. I've used it and their tank lining product is super thin and intended to neutralize existing rust and cover the metal up to protect it.

KREEM is goopy shit that people have used to plug holes and then spend the rest of their lives regretting the choice.

You might get away with an epoxy fix temporarily, but if the tank is leaking you either cut out the rotten section and weld in new steel or you replace the tank.

Is the stock tank your final goal? Or do you plan on customizing the bike?
 
POR-15 absolutely will seal SMALL pinholes, as it's intended too.


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Here is a photo from the POR site, they claim it will fix pinholes. I have only used it to prevent rust so I can't speak from experience.

Fuel%20Tank%20Sealer%20How%20to.jpg


Depending on how big the hole is, like I said, will dictate how effectively the sealer will work. Obviously if the sealer is going to drip out of the hole, it won't be very effective.

You can use a simple spot braze to seal the pinhole, or even as Tim said, an epoxy (JB weld) to cover the pinhole and give the sealer something as a backer. In this case, the epoxy will never actually come in contact with fuel, it only serves as a backer for the sealant to lie on.


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Huh well there you go. POR15 is the ticket (and I personally like it a lot). Others like Caswell coatings. There are options - just NEVER USE KREEM! :)
 
adventurco said:
Tim said:
Huh well there you go. POR15 is the ticket (and I personally like it a lot). Others like Caswell coatings. There are options - just NEVER USE KREEM! :)
If the hole is a smal pinhole, a sealer should fix it just fine. If your tank has turned into swiss cheese (see my XL350 thread) you will need to have it welded up.

So it sounds like Kreem is NOT the way to go. Funny, because I had a guy from a backwoods shop yesterday telling me to use Kreem. He was kind of a buzz kill on the bike so I'd prefer not to take his advice lol

I'm curious - how would I know if the hole is too big or not for sealant to fix it? I'd love to keep the tank as it is in great condition paint-wise and looks great. I'm building on a budget and would rather not spend a ton of money on a new tank. With that being said, I'm open to other options.

Also, where can I get these rust cleaner/sealer kits? I'm looking at amazon but would prefer pick-up if possible. https://www.amazon.com/POR-15-Fuel-Tank-Repair-Kit/product-reviews/B001NJ6JMK/ref=cm_cr_getr_d_paging_btm_4?ie=UTF8&showViewpoints=1&pageNumber=4

Adventurco - just read pretty much your entire Honda 350 thread. Nice work! And in a short time too. You'd have my bike up and running by the weekend.

I'm completely new to fixing up older motorcycles so please, everyone, speak to me like I am a 5 year old.

Pics to come soon!
 
I've had great success with every POR-15 product, including a tank on a 67 F-100, and my 74 CB450. Don't rush the process, and it's critical to ensure the tank is completely dry before using the sealer. Put a blow dryer in the tank, and let it run for a few hours.


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Mark the leaky spot on the outside of the tank (circle it with a sharpie). Empty out your tank and rinse it a few times with simple green, dry it w/compressor or heat gun. Hold it up to the light and look inside, you should be able to see light through any major holes. Sometimes a phone or camera can get better angles of the inside of the tank, too.

This is what you don't want to see:

cbc23d6299795cedf1248e79a026030f.jpg


And yes, most shops/mechanics from my experience (unless they have been doing it a LONG time) won't touch fuel tanks. Most of the time they will tell you to scrap it and buy a new tank. Which sometimes is a better option, but most of the time they can be saved.
 
540Nova said:
I've had great success with every POR-15 product, including a tank on a 67 F-100, and my 74 CB450. Don't rush the process, and it's critical to ensure the tank is completely dry before using the sealer. Put a blow dryer in the tank, and let it run for a few hours.


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Awesome! This would be so much better than scouring the internet for a new tank. Can you tell me if this amazon link has everything I would need? I believe it does but I want to be absolutely sure.
 
thefish said:
Awesome! This would be so much better than scouring the internet for a new tank. Can you tell me if this amazon link has everything I would need? I believe it does but I want to be absolutely sure.

Buy the POR-15 sealer and thats it. Forget their kit. Buy Phosphoric prep and etch from home depot, its the same stuff but more concentrated than POR-15s "prep and etch". Their degreaser does the same thing as simple green or any other cleaner/degreaser.
 
adventurco said:
Buy the POR-15 sealer and thats it. Forget their kit. Buy Phosphoric prep and etch from home depot, its the same stuff but more concentrated than POR-15s "prep and etch". Their degreaser does the same thing as simple green or any other cleaner/degreaser.

Okay, got the sealer part down. The Phosphoric prep and etch not so much. Is there a certain brand I should be looking at? I checked out the one by Klean Strip. Looks like one jug does everything I need (rids tank of rust and cleans/preps inside of tank for seal). My concern is how they want you to apply it. Sounds like the rusted area needs to be as clean as possible beforehand. But with the rust being inside of the tank,,, well you can see my dilemma. Could you simply fill tank up with product and swish around and let sit to rid it of rust?
 
Once the tank is empty of fuel, rinse with warm water and degreaser. You can use dish soap, pine sol, simple green, they all do the same thing. Flush with warm water until it comes out clear. Then prep & etch. I use a piece of scrap metal and rubber fuel line flattened out to plug the petcock hole. Dump the whole bottle in. Depending on how bad the rust is, you can either just swish it around, or rotate the tank every 10-15 minutes until you've hit all the sides. Youll know when its done. It converts the rust to iron oxide, I believe. Pour the stuff back into the jug with a funnel and save it, you can use it over and over.
 
advCo said:
Once the tank is empty of fuel, rinse with warm water and degreaser. You can use dish soap, pine sol, simple green, they all do the same thing. Flush with warm water until it comes out clear. Then prep & etch. I use a piece of scrap metal and rubber fuel line flattened out to plug the petcock hole. Dump the whole bottle in. Depending on how bad the rust is, you can either just swish it around, or rotate the tank every 10-15 minutes until you've hit all the sides. Youll know when its done. It converts the rust to iron oxide, I believe. Pour the stuff back into the jug with a funnel and save it, you can use it over and over.

Thank you, man! Been reading your previous builds - no work has been done today at my job lol Love the Honda 360 Café Racer that thing is swweeeet
 
don't give him too many praises, it ends up going to his head.....why do you think he has a pick up truck? So he has space for his EGO
HAHAHAHA!
Now go get some POR15 and seal that bitch up
 
Kamn said:
don't give him too many praises, it ends up going to his head.....why do you think he has a pick up truck? So he has space for his EGO
HAHAHAHA!
Now go get some POR15 and seal that bitch up

Good thing its only a short bed :eek:
 
Kamn said:
don't give him too many praises, it ends up going to his head.....why do you think he has a pick up truck? So he has space for his EGO
HAHAHAHA!
Now go get some POR15 and seal that bitch up

Playin' it cool, I like it. As for the POR15, is there anything specific I should be looking for? Right now, I've found their Standard Sealer 1 pint for pretty cheap. Looks like there are a lot of options though.
 
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