180-971 F1 Crane Truck

[Ravvin]

Just a tip on the timber.
When you get it, rack it for a few weeks in the same conditions that your truck is in. If the truck lives out in the weather, stack your new timber there too. I intend to rack my timber on the deck of the truck until I am ready to replace it.
If you get kiln dried timber and machine it up to the correct sizes and then fit it and leave the truck out in the weather, the timber will still swell and move a bit, no matter how seasoned it is. It's all about the moisture content.
My boss got caught out in a similar situation. We built a 1.2m x 1.2m Blackwood table out of 30mm thick timber that had been racked in our back office for over 3 years. After it was built, it sat in the back room for another few months until he had finished his home reno. In that time it never moved.
He took it home and within 2 weeks the timber top had split from end to end in 3 places. We had glued and screwed lengths of timber cross ways under the top to help stop it bowing or twisting and these had stopped the timber from shrinking as it dried out. His house has gas central heating, ducted through every room. This dried it out to almost 0% moisture content and the timber let go along the grain instead of breaking the glue and biscuit joints.
Most kiln operators dry the timber to almost 0% moisture content and then steam condition it back to near ambient outdoor moisture content. If you rack it in the same conditions that it will be eventually used, then machined to slightly undersize in width for the truck deck, you shouldn't get any nasty surprises. If you machine it dry, fit it and it absorbs moisture to bring itself up to ambient MC, you run the serious risk of the timber cupping at best, or deforming the steel channel/snapping the decking bolts at worst. Some timbers are worse than others for longitudinal or tangential expansion/contraction. If you let me know what timber you decide on I can look up the structural properties for you.

For my deck, I am a bit limited in what I can easily get down here. Of course I could always buy interstate, but the freight cost is a real killer.
The local timbers used for construction are the 3 common euc species marketed as Tas Oak. They are ok strength-wise, but have relatively low durability outdoors.
Naturally grown, (non-plantation) Southern Tasmanian Bluegum, Eucalyptus globulus, is actually a lot stronger than "Tas Oak", and is way more durable. It used to be especially sought after for railway sleepers and bridge timbers but is not as common now as these things are now made from steel or concrete. With the forest industry collapse a few years back, many of the small sawmills that still worked with this timber shut down. I have a contact in the boat building industry down in Hobart that may know of a sawmill down the east coast or around Hobart that might still mill some. The trees aren't endemic to the central north or north-west coast areas, so it's not likely anyone in my area still works with it.

Greg.

[john.k]

Years ago ,I got a local mill to saw up some boards to do a Studebaker 6x6 tray.Rough sawn was half the price of anything else,so I went with it.The boards were supposed to be 1" thick,but varied from about 3/4 to 1 1/2".Now the mill is pink town houses,and the greens have closed every mill within 200 miles.I needed some step treads recently,and was quoted $50 a metre .Stuff that ,I thought ,Ive got a yard full of big trees.Unfortunately the council has protected them,with big fines if I cut them down.Im allowed to trim 20% per year,so I got my chainsaw and cut slices out without actually felling the tree.The council inspector was there before I finished cutting.Still ,I fixed the rotted stair treads.Need to fix the fence now.Regards John.

[Chazza]

Really good advice from Greg regarding moisture content and distortion.

Years ago I made a timber-decked trailer; as long as I kept it in the shed all was well, when it lived outside it swelled up and destroyed the deck. The same thing happened to my truck.

 Either keep the canopy on to protect it, or use a shed. And don't forget to linseed oil it, at least twice a year,

Cheers Charlie

[john.k]

The Inter trays have a gap covered by a lockstrip,so swelling of the boards wont cause any buckling.At worst the wood will split,which wont compromise strength ,provided its not sawn across the grain.The last trucktray I replaced,I used boards meant for a semitrailer.The wood was about 30mm thick ,and hard as iron.The previous tray had been wrecked by loads of scrapmetal breaking the boards,but the new wood had no problem.Its been sitting in the yard unused for years and has just started to rot through now,mainly because its covered in leaves.Regards John.

[Ravvin]

Well, a bit of progress and another problem.
This afternoon it stopped raining for a while so I had another go getting the driver's side brake master cylinder off.
I had already managed to remove one nut and bolt completely, and the nut off the bolt coming through from the inside.
I tried to use a drift and hammer to knock the bolt back through, but I couldn't get a good angle and it seemed really stuck tight.
I got up on top and removed one of the short decking boards right over the cross-member that stops me getting at things from underneath.



With the board out, I was able to get a socket and ratchet on the nut and by turning it one tiny click at a time, I was eventually able to undo it.
With that out, I thought I should be able to just slide the master cylinder out, but the bolts were really tight where they went through the chassis rail and the aluminium casting of the mount.
By smacking it around with the soft-faced hammer for a while, I was able to free it up enough to get the end of a tire lever behind it and levered and wiggled it until it came loose.




It's a bit scruffy, but not badly corroded. I figured I would pull it apart, give it a clean out, sandblast and repaint.
When I opened the air chamber I got a nasty surprise. All the missing brake fluid was in there.



It looks like the rear seal in the master cylinder has failed. At least it is clean brake fluid this time. The diaphragm looks to be in good condition too.
If it isn't raining tomorrow I will strip it all down and see what else needs replacing.
I now have the fuel tank patched, sanded and primed. Tomorrow it will get a top coat and if there is time I will remove the tank mounts and give them a clean-up too.
With those off, I can also clean up the flaky paint along the chassis rail. That should make it look a bit neater.

Greg.

[Ravvin]

Well, I got it all apart and degreased. The 2 rubber buckets in the brake master need replacing. They both showed considerable wear on the edges and had a lot of small cracks when I flexed them. The rubber is pretty soft and leaves black stains on anything it touches. The spring and valve are fine. The inside bore is shiny, with no pitting or signs of wear. Same with the steel piston. The spoonful of brake fluid that was still inside was clean and green.

I gave everything a good blast in the sandblasting box, then washed it all down with wax & grease remover before painting with primer. I packed everything away before it clouded over and when I was putting the painted bits into the laundry to dry, I found I had forgotten the spring band that clamps the end cover, diaphragm and actuator body together. Really annoying. Oh well. If I get an afternoon without rain after work, I will get set up again and blast the band and a couple of brake drum backing plates that I have been meaning to do for a while.

My compressor is struggling with the sandblaster. It works fine for nail guns and air tools, but just doesn't have the flow for running a sandblaster, even the little thing I have in the box. I did see one of those diesel compressors that you tow behind a truck, for running jack-hammers and stuff, for sale on the side of the road last week. Wonder what those are worth? Should have enough flow then.

Greg.

[john.k]

Diesel compressors are great when they are in good nick,but costly to fix if anything is wrong.Its actually better to buy a really old one with a piston compressor,than a more modern vane or screw compressor.Both these require a oil separator element that has to be replaced regularly and costs $500 plus.The old[1950s] CP had the separator stuffed with wood shavings and wool,and could be rebuilt,more modern ones are like a giant oil filter.Piston compressors dont need them.Vane and screw units also have large quantities of compressor oil,200litres in a big one, that needs changing regularly.Still,sandblasting is great provided the EPA dont get ya,and hit you with a $10,000 fine.Keep a low profile.Regards John.

[Diana Alan]

Lots of old Detroit diesels have been turned into compressors have even heard of 6V53 and 6V72s having one bank converted for compressor use while the other bank provides the power.

[Chazza]

One of my maintenance jobs years ago, was to repair a wet bead-blasting cabinet. The boss had bought it on ebay secondhand and it had some corroded parts; however; when I got it going, it really worked well and was used for cleaning heads and ancillaries.

It might be worthwhile investigating one of them, but it needs a big compressor as well.

I prefer to keep it simple and cheap and use molasses,

Cheers Charlie

[Ravvin]

Thanks all, for the comments.

My sandblasting cabinet is very like the one in the pic below.



There is a rack in the bottom for you to sit the parts on while cleaning, but I tossed it in the first hour. It jambs the pickup hose and I found I have to constantly sweep grit down to the pickup as the angle of the base isn't steep enough for it to flow down itself.
It comes with a 12v fluoro light across the back. This is totally useless. There is a pleated air filter on the right end and a simple foam filter on the back. Neither do much and block up very fast. I pulled the foam out of the back one and it lets the dust out, which has improved visibility a bit. I am going to remove the pleated filter and fit a fan instead, blowing in. I wear a double filter mask when using this, as the dust coming out can't be good for you. I found I needed the mask even when I had both filters on. Just poor design and cheap manufacturing.

The only way I can see what I am doing is to lay my LED floodlight on the perspex top and stand a sheet of ply up at the back. I then drape an old sheet of cardboard from a solar panel box over the top to keep the outside light out. If I hold the part up close to the perspex, I can sometimes make out what I am doing, although I have to keep opening the lid to see it better. Once the fan is installed, I am hoping it will help by forcing a lot of the dust out the back, making it easier to see inside.

I had thought my compressor was fairly good, as it is a double cylinder type and seemed pretty solidly made. Now that I read the specs, it's only 150 litres a minute, so that's around 5.25 cu/ft. Not much at all. Definitely not enough for continuous sandblasting.

Greg.

[john.k]

On industrial filter units,there is a timed air blast that knocks the dust from the filter and lets it fall into a trap.In my experience the wet process dust collection is far better,but does use considerable water,and deposits mud that has to be removed.In industrial blasting they generally use steel grit,which doesnt deteriorate into dust.Its reckoned that garnet turns to dust in three passes of the system.I havent been in the industry for years,but we were paying a lot for garnet,in small lots its $1/kg.The payoff is production.The crowd I worked for could blast a 40ft container inside and out in about 1 hr.All done in blastrooms ,of course.I assume you all know using white sand for dry blasting is illegal,as well as being a health hazard.I have seen some funny things,like a blaster cutting slots in a classic car bonnet,and another time the council turned up to investigate outdoor blasting,and the guy frosted the windscreen and windows in the car.Regards John.

[Ravvin]

Thanks for that.
I was using garnet originally. It is $34 for a 20kg bag, think it was from WA.
The stuff I used recently is a white silica that is mined about 30 mins down the road and sold in 20kg and 1.2t bags.
It certainly strips paint and rust faster than the garnet, but seems to pulverise to dust faster. I didn't know it was meant only for wet blasting. Didn't mention that on the bag.
I wear my twin filter respirator and motocross goggles as the dust gets everywhere. After working a while, you can't run your fingers through your hair. I'm just going to use garnet from now on though, as less dust means I might actually see what I am blasting.
When I first started I was using the black grit sold at supercheap. It is very fine, dense, and turns your skin black. Not sure what it was but you go through it really fast and it's way more expensive. Something or other oxide.

[john.k]

The story of the WA garnet is a strange one.The deposit is immense ,and pure pink sand.Indian garnet is a dirty brown .Anyhoo, the WA deposit is a real gold mine,and is owned by the Exclusive Bretheren Sect.Forty years ago,it was worthless.A couple of guys camped there in the bush,trying to do something with it.Then the Govmint banned blasting with white sand.Garnet took off.Other [legal] blasting abrasives are generally dearer and less effective.In Queensland /N.NSW we have always used Ilmenite ,a by product of mineral sand processing.Its black,very fine and very heavy.4 ton/cu meter.Dont get caught dry blasting with white sand.Regards John.

[Ravvin]

I've got a week off work, with the main intention being to get lots done on my truck, but the weather isn't playing the game.
Yesterday I managed to remove the shield from under the fuel tanks, the 2 support brackets that the rear tank sits on and the brake master cylinder off the passenger side.



The shield is in very good condition, with just a bit of light surface rust and a few dents to belt out. I'll clean it up and repaint it.
The supports are a bit rougher. Here is a close-up of one of them after I cleaned it up with the wire wheel.



As you can see, the support is made up of a bent length of heavy walled channel with a length of 4" wide flat sheet steel wrapped around the back for strength and tack welded along the edges.
It looks like the moisture has gotten into the gap and caused the flat sheet steel to spall into rust chunks. When I tapped along the edge to loosen it up, a lot fell out, leaving some very thin sections of metal.

What do you all think? I could grind the tack welds off and replace the whole sheet, or I could just do the section along the bottom, up to the corner. The rest is in good condition, but it wouldn't take much extra effort to do the whole length. The other support is pretty much the same. I had a look at the 2 supports under the front tank but they look as good as new. I think this is because the oil leaking from the Abbey hoist has dripped onto the tank for years, protecting everything. 

I managed to get replacement rubbers for the 2 brake master cylinders. After chasing them through the NSN number and getting nowhere, a local car parts place managed to find modern versions. For anyone who needs to know in the future, the front seal, shaped like the lid off a camera film container, is P962. The rear one, shaped like a ring with a lip, is P1338A. Both fitted perfectly and with a tiny smear of rubber grease, popped straight back in the bore, once I gave it a light hone. I'll finish putting it back together tonight and get a few After pics as a comparison. If these annoying showers stop, I'll get the passenger side unit stripped down and see how bad it is. Then sandblast everything, prime and paint.

Greg.

[Chazza]

...
What do you all think? I could grind the tack welds off and replace the whole sheet, or I could just do the section along the bottom, up to the corner.

If it was mine, I would repair it until where the metal is in good condition,

Cheers Charlie