Does anybody know of a product that could fix an overflow tank crack.

 

Plastic, steel, aluminum?

 

The stock 79 plastic. Vertical crack on a flat side. The plastic is in good condition. It is an impact crack

 

As new OEM tanks are very flexible I would think any old tank would be brittle by now and beyond any permanent repair. I have had limited success by sandblasting then using an epoxy.

 

Possibly MarineTex. My dad was able to repair/seal damn near anything with that stuff.

 

This product?

http://www.marinetex.com/marinetexflexset.html

 

I found this product: permatex ID 09100

 

The best product is dollar bills. Pick up a good used one at a Vette flea market or grave yard. Craigs list and ebay work too.

 

new replacement tanks are not expensive, I think I got the one for my '76 around $30 this summer...found out the PO had put some silicone or something on it that finally gave way and leaked all over the garage...

 

When my buddy was installing the motor it got whacked and we were thinking of a quick fix to get it on the road until a replacement can be found. It is a all stock. I would just go to summit racing and buy something.

 

FIRE. melt it. plastic weld.
done deal.

 

http://info.craftechind.com/blog/bid...ue-for-Plastic


Stick to it! A Guide to the Best Glue for Plastic
Posted by Katie Gerard on 07.30.2013

Customers often ask us here at Craftech what the best glue for plastic is. As anyone who has tried it knows, gluing plastics can be tricky. Many plastics including Teflon, nylon, polypropylene, TPU, and PVC are notoriously hard to glue together. Why is that, you ask? The plastics that are the most difficult to glue are characterized by low surface energies, low porosity, and non-polar or non-functional surfaces. They feature no functional site or surface roughness onto which an adhesive can secure itself. In other words, they are extremely smooth and slippery, so there’s nothing for the glue to grab onto.
For this special post, we compiled a bunch of popular adhesives and materials and tested their compatibility and bonding power. We tried sticking each hard-to-glue material to itself and then to stainless steel, grade 304, to determine what the best glue was for each plastic. After allowing the adhesives to set over a 24 hour period, we tried to bust the various components apart and took note of the result.
Among the plastic materials tested, noted for their difficulty bonding with glues were Teflon, Nylon, Polypropylene, TPU, and PVC. Best glue for plasticIn our search for the best glue for plastic, we tried everything from things you’d have around the house, such as Loctite superglue, a hot glue gun, and Amazing Goop, to more specialty items such as JB Plasticweld and plastic cement for model making.
After sticking everything together (including our fingers), here’s what we came up with:
The Best Glue for Plastic: JB Weld PlasticWeld- This glue bonded nearly every material perfectly, with the exception of Teflon to itself (not surprising given the material’s use for its non-stick properties).
It spread to create a gap-free bond, filling in all the available space for strong adhesion that just wouldn’t quit, even after we tried desperately to separate the parts. The only downside of PlasticWeld is that it’s a two-part epoxy which must be mixed in equal amounts to form the adhesive, which can get messy. It also sets quite quickly, which can be either a pro or con depending on your project.
The Worst Glue for Plastic: Testors Plastic Cement- For an adhesive made specifically for connecting plastic pieces for constructing models, it did a poor job of keeping our pieces together. Even after making sure we followed their instructions to the letter, nothing stuck together despite our best efforts.
The Rest: All Purpose AMAZING GOOP- This definitely worked quite well. Despite it taking over an hour to set on TPU, it was able to bond it well to the stainless steel. However, it was easily broken apart when sticking two TPU or Nylon pieces together. For all the other trials, though, it worked well. On the downside, it is true to its name in that it’s goopy, making it less than ideal for many small, delicate applications.
Loctite Super Glue (Ultra Gel Control) – This also worked well with most of our applications, with the exceptions of Teflon to itself and Polypropylene to stainless steel. This was definitely the easiest to use, with a small dropper tip making for easy applications. There are some things to think about, however when using any sort of superglue. First, Super Glue will discolor and cloud clear pieces. best glue for plasticThe fumes even created some white discoloration on our black TPU.
NB: Never use Super Glue on acrylic! The superglue has a chemical reaction with acrylic, essentially burning itself into the acrylic. This chemical burn creates extensive white clouding that will spread even beyond the limits of where you applied the glue. Also, the only thing that can remove Super Glue is acetone. Acrylic has extremely poor resistance to acetone. Wiping an acetone-soaked tissue gently over a piece of acrylic will make the plastic look like it’s been scratched with a Brillo pad within seconds.
All-purpose hot melt glue sticks- The glue sticks were somewhat hit or miss. After the 24 hour period, we were able to break apart Teflon, polypropylene, TPU, and PVC apart with varying degrees of difficulty. The adhesive did a good job with nylon. The glue sticks bonded most materials well to the stainless steel, with the exception of TPU. This part of the project also got quite messy and stringy. There’s also always the risk of burning yourself when dealing with this molten “glue”, which is in fact made of various plastics, usually Ethylene Vinyl Acetate. So be careful!
Glue Properties According to Their Makers

All-purpose Hotmelt Glue
Sticks
Testors Plastic Cement
AMAZING GOOP All Purpose
JB Weld PlasticWeld
Loctite Super Glue (Ultra Gel Control)
Active Ingredient
Ethylene Vinyl Acetate
Ethyl Acetate
Silicone
Epichlorohydrin and Bisphenol A
Ethyl Cyanoacrylate
Bond Time
Instant bond
20 seconds
24 to 72 hours
1 hour

24 hours
Tensile strength
Not Available
Not Available
3800 PSI
3200 PSI

3063 PSI
Temperature guidelines
0° to 356°F
Not Available
-40°F to 150°F
-67° to 500°F
50° to 180°F
As always, you’ll need to run your own tests to determine the best glue for plastic for your application. This post will give you a starting point to finding the right adhesive for you!
Update!!! We are currently testing glues in order to develop a new glue guide for y'all. Are there any plastics or glues in particular you would like to see included? Let me know in the comments section below!
Check our complimentary Guide to Glues for Plastic to learn even more about what adhesives work best for difficult to glue plastics.

 

I can remember a couple of times when I used a pencil-tip soldering iron and zip ties to repair cracks in plastic. I melted the zip tie as it was being touched to the crack and it bonded perfectly. Its best to use a similar material to repair the cracked material.

 

Yes, this. Plastic welding.

 

Goop. Plumber's Goop, rather than the regular kind.

 

I think it is O'Reilly's Auto Parts, one of the bog auto parts chains, that sell a kit specifically marketed for repairing plastic overflow and wiper fluid tanks. They are out there.

 

How about just some Permatex Ultra black. That stuff sticks to everything. This is a non pressurized tank and a temporary fix right?

 

JBWeld is sealing the overflow tank on my '96 Dodge dually for over a year now. It had a leak from an abrasion rubbing against something on the bottom. Noticed it was taking a leak at idle in the driveway. Mixed a little JB weld and an hour later I was driving it again. Still waiting for it to fail.:-)

 

seriously, the time it takes to remove the tank, clean/degrease it, and plastic weld it isn't worth the effort. your tank is $29.95 new with free shipping...i'm all for fixing stuff when you can but in this case I really don't see the point.

 

I am with gungatim, get a new tank. Glue, epoxy or super glue on a 30 year old hunk of plastic in a hot environment should only be used to get you home in an emergency.