spin welding plastic

[cody]

I'm thinking about heading back to my favorite shopping mall, Bontragers and pick up a couple of tanks, they have a bunch of tanks ranging from poop tanks already set to go to water tanks that have fittings all over them in sizes ranging from dinky to 'I've got the runs' sizes, the problem with the black ready made poop tanks is they are low and flat and wide, I'm looking for bigger tanks and to get the rectangular shape I want I'd have to go into a water type tank, what I'm wondering is if anyone knows of anyone in the elkhart area that could spin weld on the 3 inch inlet and outlets I would need, I know I can get the tanks custom made at a price of several hundred dollars but being a poor person and knowing bontagers have tanks I can get for about 50 bucks each, I'm thinking all I need to do is figure out how to get the fittings put on.  I want to put a couple of 100 gallon tanks side by side in my back bay, one for gray and one for black water and then connect them so the gray tank can be used to flush the black tank.  Any ideas?

[redbus]

Cody

You can use your wood router to spin in the fittings.

[cody]

I'm just a little concerned about how to support the fitting while it's spinning at 25K, not sure what to do about clamping it in place.

[redbus]

Cody

It gets to be a problem at times on the larger holes,but I have never damaged a tank in the process. Drill the rite size hole before spinning.

[cody]

how do you clamp the fitting in the router

[redbus]

It takes a special tool to hold it in place

[cody]

oh ok, thats what I've got to find then, if it was wood, I'd have a clue but unfortunately lol,,,,,,,,,

[boogiethecat]

Spinning a three inch fitting takes much more than a standard home-sized router, because of the diameter it takes a lot more horsepower. Using a small router, you'll loose speed just when you need it and the job will be compromised if it works at all.  Commercial folks use a 1hp or more router.

I've been very successful using my monster-sized Milwaukee grinder as the power source. It spins at 15,000 but since the diameter of the fitting is larger, you get about the same surface speed as with a smaller fitting at 25000.
  If you'd like to borrow the grinder and tool I made I'd be happy to send it to you as long as you
PROMISE to send it back, and pay shipping both ways.  It weighs about 20 pounds and I'm in California...

[Van]

Ok this is a process unfamiliar to me ,can any one explain the fusing process,heat,glue or cement activated by the heat of spinning?,just wanting to learn somthing new.thanks .Van

[cody]

Will my 3HP porter cable be big enough or should I use my 5HP bosch router

[JohnEd]

Cody,

I swear!  There is absolutely no reason to "flush" your black tank.....NONE.  Drain it and whats left stays.  No harm and no "foul".  (and no pun)  I wouldn't lie to you about this shi# my man.  And never add any of that sanitizer/deoderant junk as that is only for those that are obsessed.  We won't discuss that "wand" thing for rinsing the insides....GOD!

Stacking them with the grey on top can be a challange....but can be done.  Instead install them side by side and access your grey from the top with a internal pipe that goes to the near bottom.  That way you have one less site for a problem leak.  Install an AC sump pump to transfer the water to the black tank for that important rinse.

I have seen pics of a grey tank with a hole in the center that the toilet was plumbed thru but I am sure that was a "special order" tank.

Cody, you are so very cool and helpfull.  Get away from this consideration in your design.  It is a non issue.  Also, FYI I go for months between draining my black 50 Gal tank with one using it but I use a quart of water to flush, or thereabouts.

Just MHO based on many years of experience.  You got smells?  You have inadequate venting OR a cracked vent pipe.

HTH..sincerely and still luv ya,

John

[cody]

I hadn't figured on stacking just placing them side by side with both outfeeds in the front connecting to a single drain, with a slide shutoff on each tank and one on the master drain I could control either tank, by flushing I figured to open and drain the black water tank, then close the master drain and then open the gray water drain while the black water drain was still open, that way the grey water would run into the black water tank, then open the master valve and let it all go.

[cody]

generally any smell encountered are my own fault lol, certain foods have a bad effect on me, as a matter of fact their are certain foods libby refuses to allow me to eat lol.

[JackConrad]

  Spin welding relies on the friction created by spinning to partially melt the fitting and the tank. As soon as you stop the router the parts bond together as they cool (takes less than 1 minute).
  To install the fitting, you drill a hole of the proper size with a hole saw.  The fitting has a lip that fits in the hole you drilled. The fitting has small lugs on it that mate to the adapter that you chucked into your router.  If you are standing near the tank to do this, place something between the task at hand and your legs. The spinning may send small droplets of melted plastic flying.  Jack

PS: I have not installed any of these fittings, but, I did watch the fittings being installed in our tanks.  J

[cody]

ok, good ideas, the fittings are a particular kind?, I'm learning a lot here