Best way to repair cracked plastic gas tank on boat.

[Pester]

I know..... this is pretty far of topic for SH but I cant seem to find a good workable answer for this.

The tank on my pontoon boat has some surface cracks. While it does not seem to be taking on any water one of the grandkids thought that filling it was like a car and, as a result, there is a small crack where the filler neck joins the tank. I still dont think it really leaks but I dont want to be out in the middle of the lake and have a problem. I have tried to get a replacement but the manufacturer said "we dont supply parts to anything 10 years old and older. I have looked at replacement tanks but none are a drop in fit. Even if I find one close I am going to have to pull the engine and drop the protective aluminum shroud to get to it. Seems like a repair would be better if thats possible.

Marine Tec (sp?) was recommended on one boat forum so I spent $60 and that just peeled off. Another recommendation was to get a solder iron and basically plastic weld that but I passed on that option. I was also told to smear that stuff you see advertised on TV but I dont know if that would really stick to the plastic.

So......I am back here at SH asking for some real world advice. Any guidance is appreciated.

 

[Huskydriver]

 

[918v]

JB Weld

 

[jbuck88]

I forget the number. But Sikaflex made a caulking for hdpe plastics. I'd start there.

 

[Snipe260]

Flex seal

 

[buffalowinter]

Gator Guards Gator Patch UV Cure Fiberglass Reinforced Repair Patch - 3''x6''​

$26.99
The Gator Guards Gator Patch™ UV Cure Fiberglass Reinforced Repair Patch quickly, easily, and permanently fixes cracks and holes in your boat, kayak, canoe, tank, plumbing, and more. Made to handle fiberglass, aluminum or plastic, the Gator Guards Gator Patch UV Cure Fiberglass Reinforced Repair Patch delivers a watertight, impenetrable barrier with a simple "prep, peel, stick" design that cures with standard UV light in less than an hour. Unlike ordinary patches that fall apart on anything but the flattest surface, the Gator Patch works on curved areas, dents, joints, or odd angles. You can even drill, tap, sand, and paint over this repair patch—nothing works better. Made in USA.

• UV-cure fiberglass-reinforced repair patch
• Watertight, impenetrable
• Simple "prep, peel, stick" application
• Cures with standard UV light in less than an hour
• Provides a permanent solution for boats, kayaks, canoes, tanks, plumbing, and more
• Great on fiberglass, aluminum or plastic
• Moldable around flat or curved areas, dents, joints, or angles
• Can be drilled, tapped, sanded, or painted after curing

Show less

Web ID: 2291970

 

[Pester]

thanks folks. I will start looking at those.

The filler neck comes into a rather flat area that has no reinforcement so there is some flex in that area so, at least to me, I think it would make sense to have the repair have some flex in it also.

Thanks again.....

 

[Jscb1b]

We use a soldering iron and plastic filler rod at work. Harbor freight has a plastic welding kit that we use too. The best trick I found is to use a heat gun to preheat the work area first. Disclaimer: this is on plastic fuel tanks on diesel tractors.

 

[Sean the Nailer]

I've done "some" plastic welding. Soldering-iron type, as well as heat-gun type.

The biggest and importantest point I have to share with anyone going this direction, is NOT ALL PLASTICS ARE ALIKE.

In other words, be sure you're using the correct filler as your base material. Disimilar plastics WON'T bond, and you'll only make a huge mess out of a small issue. I'm not in any way saying that this can't be done, nor am I saying that this is the method to use OR avoid. I'm only saying that further research is important before you start.

I also know what you're talking about, regarding 'older boats'. Ours was made in '84. I'm thinking that they made a 12 sided steel tank, then built a boat around it. Fun stuff.

 

[mgoodrich]

Motorcycle Fairings Repair with PlastiFix Fairing Repair Kit

How to recreate a missing piece on a motorcycle fairing

www.polyvance.com

You tube for same,

This works on hard plastic types, the you tube video description shows that it doesn't work on Nylon ,PP or PE plastics.

So do you know what type of plastic your tank is? as others have already pointed out

The more I look into this, what I linked will not work since your tank is probably polyethylene. The only way to repair this reliably is to do the plastic weld option, which you have ruled out.

 

[wvfarrier]

Pool repair epoxy and some fiber glass. Will be better than new

 

[Zebulon]

Soap. Bar soap for a quick get guy by fix

 

[n2ishun]

I know..... this is pretty far of topic

I see flames in your future.
Lots and lots of flames.
A boat may, or may not, be involved.

 

[atomic41]

I have used this to seal metal gas tanks with success. I don't know about plastic but maybe they make a product for that? It is worth searching to see.

J-B Weld Tankweld repair kit

Shop for J-B Weld Tankweld repair kit with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

 

[Caymanboy]

I know..... this is pretty far of topic for SH but I cant seem to find a good workable answer for this.

The tank on my pontoon boat has some surface cracks. While it does not seem to be taking on any water one of the grandkids thought that filling it was like a car and, as a result, there is a small crack where the filler neck joins the tank. I still dont think it really leaks but I dont want to be out in the middle of the lake and have a problem. I have tried to get a replacement but the manufacturer said "we dont supply parts to anything 10 years old and older. I have looked at replacement tanks but none are a drop in fit. Even if I find one close I am going to have to pull the engine and drop the protective aluminum shroud to get to it. Seems like a repair would be better if thats possible.

Marine Tec (sp?) was recommended on one boat forum so I spent $60 and that just peeled off. Another recommendation was to get a solder iron and basically plastic weld that but I passed on that option. I was also told to smear that stuff you see advertised on TV but I dont know if that would really stick to the plastic.

So......I am back here at SH asking for some real world advice. Any guidance is appreciated.

It's a GAS tank, with your FAMILY on it.
Unless you want to get rid of your family, replace the tank.
PS: My main business is working on botes.

 

[HPIguy]

I tried years ago on a YZ 250 to fix a small leak in the tank. Never was successful, and had to buy a new tank. And all the time I spent trying to fix it could have been time I spent riding instead.

 

[Kickin45]

Lots of different options to repair that tank.
However, being that is filled with gasoline, which many of the above repairs react poorly with, your options are to weld it or replace it.
Don’t take a chance and burn your family alive or at the very least, be stuck in the middle of a lake.

 

[ggmanning]

You need a new tank and there are many companies out their that do poly tanks in a gazillion sizes and shapes. I've been around several failed tanks over about 45 years of boats and commercial fishing. Just get a new one. Aside from that if the repair fails it can be dangerous you may F up your motor at the least Many of the water in the fuel issues I have seen over the years are from cracks, failed fittings, pick ups or vents. It's not like your car. If the system is not sealed well it sweats like a bastard in the tank.

 

[calling4life]

 

[whatsupdoc]

Replacing the tank is the ONLY real permanent repair. Or be stupid and use the advice given to you by people
that have no clue.

 

[mtwarych]

Contact your nearest RV sales and repair and ask them to "spin" a patch on for you. A spun on melted patch becomes part of the original tank and not a glued on patch.
Sudden weight shift and vibrations will pop a patch off very, very easily.
I'm not a boater but I've dealt with tanks on class C motorhomes for too many years.

 

[stevieb92]

I wouldn't even consider repairing a plastic gas tank. Replace it or prepare to be a candidate for a Darwin award.

 

[Pester]

Thanks. I managed to talk with someone at the place where the tanks are manufactured. While they no longer make a direct replacement they did share other sizes that would fit. 8-10 week delivery time.

While that is in process they mentioned that there are products that will fill in the crack and can chemically bond the patch to the old tank. I will look into that process more.

Thanks again for the input

 

[M4orturnate]

I've done "some" plastic welding. Soldering-iron type, as well as heat-gun type.

The biggest and importantest point I have to share with anyone going this direction, is NOT ALL PLASTICS ARE ALIKE.

In other words, be sure you're using the correct filler as your base material. Disimilar plastics WON'T bond, and you'll only make a huge mess out of a small issue. I'm not in any way saying that this can't be done, nor am I saying that this is the method to use OR avoid. I'm only saying that further research is important before you start.

I also know what you're talking about, regarding 'older boats'. Ours was made in '84. I'm thinking that they made a 12 sided steel tank, then built a boat around it. Fun stuff.

This is correct. And certain plastics won't weld either. 2 part epoxy can work but may require a adhesion promoter and to be properly prepped to stick. If there is anywhere you can slice a little bit of and use that as your filler rod it may work.

 

[Sniperwannabee]

Contact your nearest RV sales and repair and ask them to "spin" a patch on for you. A spun on melted patch becomes part of the original tank and not a glued on patch.
Sudden weight shift and vibrations will pop a patch off very, very easily.
I'm not a boater but I've dealt with tanks on class C motorhomes for too many years.

Thanks for posting, never heard of that