Installing a Thetford Curve

[Riwright]

I recently removed the Thetford Electramagic and installed another Thetford product, the "Curve."

Photo album of the install:

http://photobucket.com/albums/rr297/...t/Public/Curve


Thetford's product page:

http://www.thetford.com/HOME/PRODUCT...6/Default.aspx

A couple of videos:
http://youtu.be/w0lJ6FbmdCM
http://youtu.be/RwNFB6NVGf4


It is similar to the Thetford Porta Potti in operation. It holds 4 gallons of fresh water and 5.5 gallons in the black tank.

There are two parts to the unit. The top part consists of the seat, the bowl and an integrated fresh water tank. There is a button that operates a battery powered flush pump. The bottom part is the black tank. It has a blade valve that separates the black tank and the bowl. There is a spout that is used to dump the waste and a button to release air to let the black tank empty smoothly.

It holds 4 gallons of fresh water and 5,5 gallons of black.

There is no connection to the dump valve below the trailer. When the toilet becomes full you remove the top part and set it in the tub. You then walk the black tank to a permanent toilet and dump. Similar to a cassette toilet in operation.

Since the entire unit comes out, it is easy to clean. You can put it in the yard and hose it down if you like.

You will need:
3/4 plywood at least 16 X 19 (used to make a riser)
Kilz spray sealer/primer
Grey spray paint
Sandable and paintable wood filler
Coarse, medium and fine sandpaper - sandpaper drums that fit a drill are nice or you can use a wood block
Jigsaw with a fine blade
Carpenter's pencil
Sharp knife
3" plastic test cap (I didn't use a black rubber one, it stuck up too much)
Silicon adhesive
Grey caulking
Rubber Mallet
Drill bits
Drill
Thetford Curve
Thetford Hold Down plate for the Curve
A bucket of chicken

To install you first need to remove the old toilet. Study Bill's document, it is a good guide. The only thing I ran into was the little wedges were installed backwards. Study the doc and feel around and you'll see which way yours are facing.

I was concerned about releasing an unspeakable evil that must remain sealed for all time when removing the old toilet. The Internet said to sacrifice a small bird. I was unable to catch one. I bought a bucket of chicken. It seemed to do the trick.

Seal off the old toilet flange with a plastic test cap and some silicon. Cap off the old wires and spray paint the marks on the back wall (Rustoleum Antique White). Remove the closet bolts that are sticking up. Remove the plastic piece that keeps the foot of the old toilet stable.

Cut a piece of 3/4 plywood to a 16 X 19 rectangle. You want something that covers the entire area where the toilet might go. Set the plywood into place and bang hard with a rubber mallet. The screws for the toilet flange will make marks in the plywood.

Using the marks as a guide cut out a hole for the flange. Put the plywood back in place and drop it over the flange.

Put the hold-down plate on the bottom of the toilet. Fit the toilet into position and mark the position of the hold-down plate on the plywood with a carpenter's pencil.

Position is important. The lever for the blade valve is on the bathtub side. There is a toilet paper holder there if you want to use it (I didn't see much use for it.) There is a latch that separates the two halves in the back. Put the toilet far enough out from the wall to get to it.

The toilet needs to be a little to the right (away from the tub) as you face it. Don't center it over the flange, you won't be able to operate the blade valve. Don't put it so far away from the tub that the bathtub side of the toilet is not well supported or the hole for the flange is exposed.

Pull the plywood up. Score the plywood with a knife to minimize splintering. Cut out the plywood with a jigsaw using a fine blade. Rough sand the edges and make sure the plywood is the same shape as the plate.

Take the wood filler and smear it over the edges of the plywood. Let it dry and sand it very smooth with fine sandpaper.

Remember that only the very front part really shows so focus your efforts there.

Paint the plywood with at least two coats with Kilz sealer and primer. Get all surfaces and edges including the hole for the flange. You want to protect it from water as much as you can. Paint with gray spray paint, two coats.

Install the plywood riser and the hold-down plate using four screws long enough to penetrate well into the floor of the trailer.

Using a gray latex caulk, caulk the seam between the riser and the floor and the riser and the hold-down plate. Clean off any excess.

Once it all dries you're done.

[B_and_D]

Very nice.

As I noted in a separate thread, removing the old toilet can create a loose waste line. My comments are in the post link below:

http://www.trailmanorowners.com/foru...6&postcount=53

[Riwright]

Glad you re-posted, looks like the entire thread was lost.

I checked underneath and did find some play in the plumbing down there. I put spray foam into the gap between the black pipe and the hole in the floor that it travels through. I went all the way around and trimmed the excess the next day. This did a pretty good job of taking out the play in the pipes.

I did the same and love the new toilet. Easy to remove and dump. No Smell.

Did you leave the black waste line in place?

Originally Posted by Jacob B

Did you leave the black waste line in place?

I did. Most of us install a false floor to cover the floor flange and a pipe plug. Reading your other posts about the damage you suffered, that may not be an issue.

Thanks again. You can ignore my other message on the other thread since I asked the same question again not realizing it was you!

[Lesherp]

I have given some thought to replacing the Thetford Electramagic. I am wondering if you considered the Sealand 711 and why you chose the Curve over it.

If I remember correctly the Sealand could be drained using the same hookups as the Eletramagic. You always have to dump grey water anyway and the Sealand can be dumped at the same time you do that, whereas the Curve would require a trip to a bathroom somewhere while the trailer was still up. Is there some advantage to the Curve I am missing?

[Riwright]

We do a lot of dry camping where hookups and dump stations are hard to find. With the Curve I can just take the black tank to the local pit toilet and dump it.

We generate about 5 gallons of gray water per day. Usually I cart it to the pit toilet or dispose of it in some manner that the campground allows.

If a dump station is available and the trip is short I might use it. I throw the black tank in the back of the pickup.

I've only used a dump station once since I installed the Curve. I found it was a little clumsier to dump the black tank at a dump station than it was to use a toilet. It was good to be able to hose it out inside though.

If using a dump station isn't a problem for you then you might be happier with the Sealand.