Installed New Gas Tank...Beautiful

[Tom M]

Hi Joe,

The Guzzi tanks are made by Acerbis, who make lots of plastics used on dirt bikes. I know KTM used Acerbis plastics in the past, don't know if they still do. Anyway, try digging around some dirt bike forums to see how they repair ruptured tanks. A call to a KTM shop might help too.

[joe camarda]

If (a big "if") anyone is still following this thread, I'm in contact with the urethanesupply.com people to (1) determine what my tank is made of and (2) which of their plastic welding products I should use. Unfortunately it looks like a $250 outlay for the kit I might need

 

Input is still sought and appreciated.

 

Quick response from urethanesupply.com

 

"Joe,

 

PA is nylon. You will want to get the ATV Pro Welder and some 5003R6 Nylon Welding rod. The kit comes with everything you need to do the repair (except the Nylon rod). You will want the Pro model for two reasons. It has a higher wattage element, which you'll want for welding nylon due to its high melting tempurature and it comes with some stainless steel reinforcing mesh which adds a lot of strength and helps seal pinholes.

 

Let me finish by saying....Lucky you, owning a Moto-Guzzi, they are very nice bikes, super reliable too!

Sincerely,

 

Scott Bixler

Product Development/Marketing

800-633-3047

 

Urethane Supply Company

1128 Kirk Road

Rainsville, AL 35986-6038 USA"

 

So I ordered the items today

 

Tom...Thanks, my local KTM dealer seemed helpful, but said he would have to track down the info himself.

[jrt]

You might be able to turn this into lemonade. A lot of folks complained about cracking the V11 sidecovers early on (I did, and had it replaced under warranty). You could contract out and repair some of those (might as well use the welding iron you're buying). Also, all the new tanks (breva 750/1100, Norge, etc.) are probably the same plastic.

 

I think you can weld almost any plastic- polypropylene, polyamide, and I bet even polycarbonates.

[joe camarda]

You might be able to turn this into lemonade. A lot of folks complained about cracking the V11 sidecovers early on (I did, and had it replaced under warranty). You could contract out and repair some of those (might as well use the welding iron you're buying). Also, all the new tanks (breva 750/1100, Norge, etc.) are probably the same plastic.

 

I think you can weld almost any plastic- polypropylene, polyamide, and I bet even polycarbonates.

 

Today I welded my dog to the garage door. That was kinda neat

[jrt]

[docc]

I repaired my side covers and starter cover by either epoxying fiber board or using fiberglass an the inside of the part. Low tech but effective, I suppose.

 

Is it my imagination or is urethane starting to creep into threads?

[huub]

Joe...thanks for the advice. I just visited POR15 website and it looks like what I need. However, the site did NOT mention using the "US Gas Tank Sealant" on plastic tanks.

 

Have you used it on plastic tanks?

 

Also, any recommendations re the use of a "re-inforcing material" for exterior applications? I will probably patch from inside and outside as well.

 

Thanks again

 

Joe,

 

I once repaired a plastic tank with tank cure. Works great. It's an epoxy that you can poor in the tank. The only thing you have tot do is turn it around for some minutes and than wait several days until it's dry.

 

see http://www.tankcure.nl

 

 

Huub

[Greg Bender]

Here is a product that may be of use:

 

http://www.eclecticproducts.com/sealall.htm

 

If not a permanent fix, at least something that can be used in an emergency to get you going. Available in a lot of stores (Wal Mart, etc.)

[Guest Boingo]

Joe,

Don't know if you still need help here or not, but I was a plastics engineer for years. What you have is a glass filled nylon (probably made by GE.....yup the bulb company). Because it is made with glass fibers it will be difficult to bond but it is do able. PA6 is an industrial standard for nylon that has 6% glass fiber added. Actually stong stuff, but not strong enough here as you see. The other symbols you see are what we call a "date wheel" inside the mold. It indicates to the manufacturer what day/month/year the part was manufactured for warranty issues. Don't worry about that cause it's not gonna help. To bond nylon is actually simple, but you will need access to both sides of the crack which may be a problem. If not, here are some easy steps. Clean everything.....and I mean clean. Super clean cause if it's not it won't seal properly. Get yourself some HCL acid. Not the easiest suff to find but with enough research anything is obtainable. Sand away the paint from the cracked area...about a half inch all around. Make sure it is REALLY clean both inside and out. Now the easy part. Take a Q-Tip and soak it with the HCL acid. Rub it up and down the crack re-wetting as necessary on one side only. Shortly you will see the plastic start to "melt". Apply water quickly to inert the acid and keep the plastic from melting completely. The goal is to melt the plastic chemically just enough to rebond the two sides. Try to get about 50% depth, and it will be hard to tell but you'll get the feel for it quick. Wipe it off and re wet with water a couple of times. Dry it completely. Do the same thing to the other side (the other 50% depth). Let it stand for a day or so and sand down the imperfections, fill any problems you see with body filler and repaint. It will bond just as strong as a newly injected part. Welding of nylon will work, but will leave "stresses" in the plastic around the heat effected zone of the weld. Not to mention you cannot get glass filled welding rod either, so it's like mixing oil and water. Not a good idea in a gas tank and due to vibration will most likely crack just outside of the original weld and you will be starting all over again. Basically welding something on a vibrating platform will only lead to more problems and in your case a new tank. Hope this helps and if you need further assistance please let me know.

[joe camarda]

Hi Boingo.... Welcome aboard!

 

I did manage to plastic weld the tank and was pretty confident (actually very confident) of the weld until I read your post.

 

I dremelled a V shaped cut (about 2/3 of the way through the tank) along the crack and filled it in with the welding material. I then melted the adjacent tank plastic and mixed the two. Then I covered everything up with another layer of the welding rod. Although it looked effectively done it looked kinda crude but it was not visible anyway. Then my paint guy prepped it and the whole tank was repainted.

 

I've checked it often figuring that the slightest leak would "blister" the overlaying paint. But it gives no indication of any problem.

 

I hope I'm right. Never the less I'll double my vigilance.

 

PS Love Seattle. I was there last year for my daughter's wedding.

[mike wilson]

Get yourself some HCL acid.

 

Thanks for the tip. What strength acid are we talking about? It comes in a range from something not quite as strong as vinegar to something that has corrosive fumes that will damage your eyes and lungs in a very short time. As you are talkiing about dipping a Qtip in it, I assume you are talking about something like 2molar (2normal). The sort of stuff you play with at school.

[Garsdad]

At this point, I think it may be cheaper to buy a used tank (have it checked for leaks before hand) and have it painted.

[Guest Boingo]

Thanks for the tip. What strength acid are we talking about? It comes in a range from something not quite as strong as vinegar to something that has corrosive fumes that will damage your eyes and lungs in a very short time. As you are talkiing about dipping a Qtip in it, I assume you are talking about something like 2molar (2normal). The sort of stuff you play with at school.

 

Correct type. It will take a while to begin to melt, but better to play it safe and take your time. Don't be in a rush and it will all work out perfectly.

 

Joe, thanks for the reply. Dependand on how hot the rod was when welding will directly affect the heat effected zone. The cooler the better. Just keep checking on it and if it looks good and strong, it probably will last quite a long time. Congrats on your daughters wedding. I hope it was summer when you were up here cause it's perfect during the summer. Crappy right now, but summers are awesome. If you find your way back here, send me message and I'll take you out for a drink. Not only is it nice in Seattle, but the people are decent too! Cheers!

[Skeeve]

Get yourself some HCL acid. Not the easiest suff to find but with enough research anything is obtainable.

 

FWIW the muriatic acid sold in pool supply houses, etc. is HCL. Easiest & cheapest way to get it if you need it; it's used for cleaning concrete.