Balancing Act

My list of to-dos for Cecil is nearing an end - at least until I want to do something drastic, like replace the floor.

I really only had two things left that I wanted to do.  One was to install a license plate holder.  The other was to install Centramatic balancers on the wheel assemblies.

Centramatic balancers are very simple but very cool.  They dynamically balance the wheel, tire and hub assembly for near-perfect balance when driving down the road.  It's always wise to balance your tires after they are assembled on the wheels.  However, the hubs and tire and wheel may not be balanced when it's all put together on the vehicle.  Even if the tire is out of balance, the Centramatic balancer will correct for any irregularities.

How does it work?  In a nutshell, centrifugal force moves tiny weights in a circular tube to the area that extra weight is needed when the wheel is in motion.  That may seem hard to picture, so check out this video from the manufacturer.

Vibration can do all sorts of unintentional things.  First of all, it can result in premature and irregular tire wear.  But more importantly, the shaking that occurs do to imbalance can move things around in the trailer, cause fittings to work loose or result in other damage inside the vehicle.  The smoother the ride, the better, as far as vibration goes.

Centramatic makes dynamic balancers in all sorts of sizes for vehicles as small as motorcycles to as large as 18 wheel tractor trailers - and everything in between.  You can call them and discuss your application and they can help you select the balancer that's right for your application.

My order for two balancers consisted of two rings approximately 10" in diameter with 6 holes to accommodate the lugs on the hubs.  The outside of the ring was a circular tube and when you move the tube around you can hear what sounds like BB's moving around inside.

Installation is easy.  The first step is to remove the hubcap and then remove the wheel from the trailer.

With the outside of the wheel facing the driveway, I can see the inside of the wheel.

I can orient the balancer so that the ring faces the wheel.  The holes in the balancer aline with the holes in the wheel and it just gets sandwiched between the wheel and hub once it's installed.

Looking at the hub, you can see the six lugs.

There's plenty of room for the ring on the balancer to face inward toward the hub too - so the balancer can be installed facing either direction.

All I have to do now is put the wheel back on and re-tighten the lugs to 95 ft-lbs of torque.  Then I have to do the other side.  

Cecil is in for smooth sailing now when he cruises down the road.

Dump Valve Redux

Continuing the saga of replacing the original Thetford dump valve on my 1961 Safari, I needed to obtain an adapter that would enable me to go from the 3.5" bolt spacing and 2" hole opening to a 3.75" bolt spacing with a 3" hole opening.

You can actually find an adapter plate for this purpose on Vintage Trailer Supply but I had three major concerns with their offering.

First, their adapter requires you to orient the new dump valve handle on an angle and my trailer requires the dump valve handle to go straight rearward, though the bumper.  For any other angle I'd need to cut new holes through the frame and I'd rather not do that.  Plus I want to use the old Thetford handle and linkage.

Second, the VTS adapter is made out of aluminum and I'm concerned it might not hold up to "black water juice".

Third, the Valterra valve has two gaskets, one on each side of the gate valve, and the gasket needs something to support it.  The VTS adapter is flat, and doesn't have anything to support the gasket.

When you look at the valve without the gaskets, you can see the gaps on each side.  Without a good gasket seal, the black water tank could leak past.

The "collector" downstream of the new valve has a lip, or wall, that extends into the gasket - pressing it into the valve for a good seal.  My new adapter needs to have something like that as part of the design.

The rubber gasket has a 3-demensional profile so it can't just be smushed up against a flat plate.

With the gasket in place, you can see how the Valterra parts are engineered for a good seal.

I'll need to custom-make a new adapter and that's going to require precise machining.

So what's better than having your own machine shop???   Having a friend with his own machine shop.

I drew up a sketch and brought my new and old parts to my friend and he custom-made an adapter to fit my needs.

We chose Delrin for the material.  Delrin is a black, high strength, machinable plastic.  It will hold up well to the black water tank contents and also provide a strong adapter for the new valve assembly.  Another option is a free-machining stainless steel - and I could make a good argument for that too.

As you can see, on the downstream side of the adapter, there's a wall integrated into the plate, just like on the collector-side of the valve.  This will give the valve a good seal on the black water-side.

In order to get the bolt patterns to line up properly, I had to offset the 2" and 3" holes, so they're not centered.  That shouldn't be an issue though - the contents of the tank drop straight down by gravity.

The tank-side of the adapter has an 1/8" o-ring, engineered to compress 20% when the plate is secured to the brass black water tank flange.  The other four holes in the adapter are for the valve assembly.  They have threaded inserts installed so the valve bolts can get a good grip.

If you look closely you can see a little of the 2" hole is outside the edge of the 3" hole.  That's because there wasn't enough space to accommodate the threaded inserts in the plate.  If I went with stainless steel I would have been able to move the hole pattern a little and have the 2" hole inside the 3" hole... oh well.  This should work fine.

My collector only has one inlet from the gray water side.  So I need to do something with the 1.25" line coming from the shower.  Before I start anything else, I will prime and paint the frame while I have access to it.

The first thing to get installed is the adapter plate.  I'm using 1/4-20 stainless cap screws with blue locktite.  I don't want vibration to loosen these screws and I don't have the space for lock washers.  I might have to someday take this plate off though - so blue locktite is a good choice.  A little silicone around the o-ring will ensure a good seal.

The adapter is in place.  Now to try the new valve and collector assembly.

That looks pretty good.  The outlet of the collector will extend about 1.5" below the belly pan.  That's perfect.  I took the handle off the valve so that I can jury-rig something to extend it out the back bumper.

My old Thetford valve had a clevis-style joint.  I debated trimming the clevis portion off and drilling / tapping a hole in the end of the rod so I could screw it onto the valve rod.  After some thought, I used a short piece of angle iron to reuse the clevis joint and it also provides a little needed offset.  This was a perfect solution.

Here it is installed... everything pulls and pushes smoothly.  A little more blue locktite is used to keep it from working loose.

I had to work a little black magic with black ABS plastic fittings in order to get the shower drain to go into the gray water drain.  I couldn't find a fitting to go from metal to black ABS so since they are both 1.25" lines I just sealed the connection with "goop".  It should work fine.

The old sheet metal cover over this area was galvanized steel.  It was rusted and raggedy in numerous places so I bought a new aluminum sheet to cover the opening.   It was a little tricky to get my hole in the right place but I got close enough for government work.  Wide-flanged rivets secure it all in place.

A Rhino-flex 90 degree elbow will allow me to connect my sewer line in a campground or dump station.

This renovation was a LOT of work but I have to say that I'm very pleased with how it turned out.  From the outside you would have no idea that the dump valve has been replaced.  It all works just as it did in 1961 - but now it's serviceable.

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Back in the Saddle...

Well, Cecil survived the Winter unscathed, thank goodness.  I stopped by the storage yard a few times  over the months to check on him and each time everything looked safe and sound.

One time I saw some condensation inside after a huge snow storm.  So I bought a bucket-o-dessicant that is used as a dehumidifer and it kept everything nice and dry inside after that.

Anyway,  Cecil is back in my driveway to continue some of the renovations on my to-do list.  The list is getting very short though.  The main thing left is to replace the old Thetford dump valve so I can use the black water tank again.

Airstream used a brass Thetford valve from 1959 through 1964 that is no longer serviceable and the modern hoses and fitting don't accommodate the old fittings.  The only option is replacement and in order to do that, I have to get the current one out.

Now that I have a new axle, the trailer rides about 4" higher than it did when I first got it.  I also lowered the tongue a few inches and that gave me even more clearance at the rear.

Someone long ago had cut a hole in the belly pan and covered it with galvanized steel sheet metal.  That will have to go but my first step will be to take it down.

I'm glad I opened this up... the drain line from the sinks has been patched and it has cracked.  There was a TON of very fine silt inside the belly pan.  That confirms my theory that at one point this trailer was submerged in a flood of some sort.  I don't see any obvious water damage - just about 100lbs of unnecessary dirt on top of the belly pan.

At least now I can see the dump valve and what it will take to remove it.  There are four slotted bolts that hold it to the brass fitting imbedded in the fiberglass tank, on the right side of the photo below.

Looking upward, the shower drain comes from the forward side - the right side of this photo.  The two sinks drain into the street-side.  They don't have dump valves.  I could install a small gray water tank on the street side of the trailer, I suppose.  But I already have a "blue boy" portable gray water tank to use if needed.

Here's a shot of the street-side and the silt inside the belly pan.  Yuck.

I had to use a lot of penetrating oil and my impact driver to get the four 1/4-20 bolts holding the valve out.  I got three to come out clean but the fourth broke off.  So I had to drill it out and re-tap it.

Here's a tank-side view of the valve.  The gate no longer moves and this valve has been stuck open - which is fine.  I'd rather have that than a full tank of "stuff" to deal with.  The tank is bone-dry thankfully.

Here's a shot of the tank without a valve installed.  Now I have to figure out how to put a modern dump valve in place, how to make it accessible for use, and how to reconnect the shower and sink drains.

Here's the view looking up into the tank.  If it wasn't so dark you'd be able to see the business end of the toilet.  It's position directly above the drain hole.

I'll show you the finished project when I figure out what to do next.