I put this question in the tool section because I need to know the BEST tool for attaching 2 plastic halves together. Heres what I have, its a plastic coolant tank,the 2 halves are pressed together. I am guessing heat formed. This is a brand new replacement tank. The old one leaked at the seam. Warranty replaced it, while I have the new one on the bench, before I install it,I would like to ,seal-glue-weld the seam to make SURE it does not leak again. Has a pressure of 15 pounds and is made out of some type of hard plastic. Any suggestions?
plastic welding
- Thread starter SwampCat
- Start date
Zeke
Well-known member
It's possible that you are seeing the parting line of the mold. I don't think in many cases a part is joined post forming. You might want to attach a pic so we can see.
AFA strengthening the seam, you need to know what plastic you are dealing with. Milky white plastic for tanks can be Nylon. That takes a higher heat than others. You will need the appropriate filler material as a urethane filler won't work.
AFA strengthening the seam, you need to know what plastic you are dealing with. Milky white plastic for tanks can be Nylon. That takes a higher heat than others. You will need the appropriate filler material as a urethane filler won't work.
CHADD
Well-known member
I plastic weld radiators with good luck. Any type of plastic pressure tank should be close to the same material. Nylon like Zeke mentioned.
I use this
http://www.harborfreight.com/plastic-welding-kit-80-watt-iron-67102.html
I have repaired many plastic items that i would of just tossed out and replaced.
This website carrys lots of kits and how-tos.
http://www.urethanesupply.com/identify.php
I use the HF plastic welding iron and zip ties. Most zip ties are nylon also. I use them as a plastic filler rod.
I use this
http://www.harborfreight.com/plastic-welding-kit-80-watt-iron-67102.html
I have repaired many plastic items that i would of just tossed out and replaced.
This website carrys lots of kits and how-tos.
http://www.urethanesupply.com/identify.php
I use the HF plastic welding iron and zip ties. Most zip ties are nylon also. I use them as a plastic filler rod.
Well its a black, hard plastic, not the white flexy type Wish I could post a picture, my computer skills fail compared to my mechanical ones. This tank has thick beefy edges on the 2 halves, with some type of gasket material sandwiched between them. Looking for some, piece of mind, type of insurance before I go to all the trouble to install this thing again. The tank you can hold in your 2 hands, and it has 9 lines on it,
plus a radiator cap.
plus a radiator cap.CHADD
Well-known member
Should be the same principal as fixing a radiator.
Zeke
Well-known member
That is hands down the stupidest video ever.
It's probably an HDPE tank. There's really no reliable glue/epoxy that can be used on polyolefins. A lot of tanks are blowmolded/rotomolded, but there are tanks that are molded in two halves and then hot-plated welded, vibration welded, infrared welded, etc. It sounds like the tank you have was molded in two halves and bonded with some kind of sealant. What's the tank going on?
TheGrooveking
Well-known member
I've welded more than a few miles of plastic, mostly PVC, CPVC and some polypropylene. The PVC and CPVC I used heated compressed air welders as with all welding cleanliness of the surfaces to be welded is key, also do not overheat, charring the weld will cause failure, so slow and easy is critical as is cleaning(deglossing) both your rod and pieces is needed.
When welding polypropylene you must use nitrogen instead of compressed air, also NOOOO moisture, you air or nitrogen must be dry. Dry nitrogen you ask? Of course nitrogen when taken from a highly compressed state to lower pressure will cause condensation to form.
Make sure you use the right rod, PVC for PVC, etc. For some thin plastic ultrasonic welding may be necessary. When I get home I'll have to get my welder info, I bought in the late 80's, and the only thing to go wrong is no air flow over the heating element, thus causing it to crack. So always remember to unplug the electric and let the air flow until the welder's output is cool to touch.
TheGrooveking
When welding polypropylene you must use nitrogen instead of compressed air, also NOOOO moisture, you air or nitrogen must be dry. Dry nitrogen you ask? Of course nitrogen when taken from a highly compressed state to lower pressure will cause condensation to form.
Make sure you use the right rod, PVC for PVC, etc. For some thin plastic ultrasonic welding may be necessary. When I get home I'll have to get my welder info, I bought in the late 80's, and the only thing to go wrong is no air flow over the heating element, thus causing it to crack. So always remember to unplug the electric and let the air flow until the welder's output is cool to touch.
TheGrooveking
RBailey
Well-known member
"Plastic" radiators are normally some sort of nylon, that can be plastic welded but you normally need to preheat.
Check very carefully to see if there are any markings on what type of plastic it is as that will make the question / answer easier.
Urethane Supply have a great site with loads of information.
(I have one of there welders and it is great.)
One of my projects here
http://svdp-racing.co.uk/wp/?p=480
Check very carefully to see if there are any markings on what type of plastic it is as that will make the question / answer easier.
Urethane Supply have a great site with loads of information.
(I have one of there welders and it is great.)
One of my projects here
http://svdp-racing.co.uk/wp/?p=480
If it was remotely practical to do, why wouldn't the manufacturer already be doing it?
egnorant
Well-known member
To save money, to meet federal or Union guidelines, to simplify the assembly process, pick one or two reasons.
Is this the cheapest part that will satisfy the warranty period seems to be the rule.
Seems like the original question is that he found a weakness in the original design and is seeking ideas to insure that this weakness never bothers him again.
Bruce
Bruce,seems you ran across this problem before. I went the experimental route and Rhino lined that seam. Turned out to be the only logical option, Epoxy did not work. 5 minute plastic bonder was not cutting it.Plastic welding worked on the part I could get to ( practised on the old tank ) Rhino guy says its NEVER GONNA LEAK AGAIN, short of a lightning strike
time will tell.
time will tell.I have a coolant tank in my car, its a tough job doing an R&R due to placement of one of the mounting bolts and going in the rear corner of the engine bay tucked under the fender. Sometimes they leak, $130 a new one, which sometimes leaks. They may have looked at various sealing aids and decided the risk from a chunk flaking off and causing trouble inside the motor etc wasn't worth the trouble from a few that leak and need to be replaced.
Attachments
TXOMFS
Member
I couldn't even watch all of it.