Slow Build in Oz

[MickinOz]

Progress has been slow, but not non-existent:
After much measuring I decided to use the new wheels I bought.
Why much measuring? Well, it's difficult to measure but the hubs on the trailer are only about 4mm wider that the embossed rim that constitutes one of the mating surface on the new rims.
i.e. The rims are stud-centric and have pressed inner and outer rings either side of the stud circle. These constitute the mating/support surfaces.
You torque the lug nuts and these two rings make contact with the hub and that's it. The question - is the hub big enough diameter to mate with that outer ring?
In the end, I coated the inside of the rim with black marker, mounted the rims up and torqued the lug nuts to 60 ft-lb.
When I took the rim back off, I had a nice black circle on the face of the hub about 2-3 mm in from the edge. So I was convinced the rim was mounting up to the face of the hub properly.

The other thing we've done is fabricate new spring mounts. the old ones consisted of fairly light brackets welded to very thin angle ~2 mm that bolted to the trailer frame. Far too light for my taste.
We copied these in very heavy steel ~4 to 5 mm wall thickness. Should help me sleep well.

Another positive - went to dinner with the family at a local pub. My brother in law was quite upbeat.
He said, "I actually saw a teardrop camper today. NOW I get it. What a great idea."

[MickinOz]

Ah, decisions, decisions...........

I really want to use the super simple construction methods:

No insulation. It seems the most important thing is for insulation in cold weather - and we seldom fall below 32F here.

So, cut solid floor panels (1/2 or 3/4 ply) to size.
Soak all surfaces in the mix, dry and paint underside with some sort of liner.
Or, I can get my hands on large pieces of scrap 2mm thick HDPE landfill liner, which seems a possibility for protecting the underside of the floor.

Screw the prepped floor straight to the top of the trailer frame with Tek screws. Could use something like Sika 252 as a locking adhesive on the thread of the screw.
If I were to use the 2mm HDPE membrane, I'd simply sandwich it between floor and frame. It'd act like a gasket to stop water getting in, I think.

Walls would 1/2 inch ply attached to the side of the trailer frame in similar fashion.
Like the sidemount "simple benroy" option here, http://tnttt.com/viewtopic.php?f=21&t=19442 , but with the screws into the steel frame.
Sealing with something like Sika 252.

Spars (purlins?) across the top and any other framing will be Tasmanian Oak I think. It's listed as a stock item on the Bunnings website and seems quite cheap.

That will be the approach, I think.
Planning to sheath in PMF for water proofing. It may be wishful thinking, but I also believe it will add some strength as well.

So, I'm looking to build as simply as possible.
The trade off is that the width inside will be a touch over 55 inches.
Not wide enough for a standard Australian queen size mattress which is 60 inches wide.
Would be able to use a standard Australian double mattress - 54 inches wide.

Better than the 48 inch (or less) width you get with a trailer based on 8 x 4 sheets.

The missus has decided that will be good enough. Which I'm pretty happy about.
I've found that clearances will be just too tight trying to build a box with 60 inch inside width.
I'd really need to put a longer axle in to do it.

A question I can't seem to search out an answer for:
Can you waterproof your ply with the polyurethane/turps mix, then glue and screw it with polyurethane adhesives?
Just thinking it'd be a lot quicker and easier if you could pretreat everything while it is in pieces.
And it might be darn useful for preserving your timber if a joint should leak.

[edgeau]

Tassie Oak is a good choice strength for weight I think. I have glued pieces treated with the mix and nothing has come apart yet.

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[Westy]

Screw the prepped floor straight to the top of the trailer frame with Tek screws. Could use something like Sika 252 as a locking adhesive on the thread of the screw.
If I were to use the 2mm HDPE membrane, I'd simply sandwich it between floor and frame. It'd act like a gasket to stop water getting in, I think.

Give 50mm wide Denso tape some thought. Use that as the sandwich between the ply and the frame. No moisture will get by it.

At about $10 for a 8 metre roll you can't go wrong.

[MickinOz]

Had lunch with the lads on Friday.
This week our builder mate was working in town so was able to join us.
Timber discussion ensued.
"Have you tried Port Augusta?"

"Well, no, actually. Being 60 miles further from the capital than us, wouldn't freight kill it?"

With that slightly sardonic Greek lift of the eyebrow that he does so well, he took a sip of his raspberry coke and said "Maybe."

So I call Mitre 10 at Port Augusta.
Talk to "Peter"
"Mate, just what we need - someone who wants to buy some plywood".
"We happen to have some bundles of 15mm and 17mm structural ply we have discounted to clear 'em out."

So off I go, armed with my shopping list and a side order from one of the lunch partners.
We ask at the front counter for "Pete who does the timber sales."
Little sweetheart behind counter saaid, "that'll be Pig Pete" and points out this grizzled old man-mountain "Big Pete". I'm a touch over 6 feet and this guy made me feel short.
Loaded the gear on the trailer by himself.

15mm CD with A bond, $58 per sheet
17mm CD with A bond $64 per sheet

This works out $21 per sheet less than Bunnings and only had to drive 120 miles instead of 250.
Sweet.

Took the missus and she even limited herself to one new light fitting only, so a good day all round.
Amazing what 105 degrees does for one's enthusiasm for shopping.

[MickinOz]

So, progress so far:
Fabricated new spring mount rails.
Took off the 2mm thick old ones, which were held on by 3 7/16 machines crews each side. Some of these were loose.
Fitted new 5mm rails with mounts welded on. Drilled holes out and fitted 12mm metric bolts. Galvanised 4.8 grade torqued to 28 ft-lbs per recommendations from bolt suppliers.

Cut off the bilge boards that used to support the boat that lived on this trailer.

Removing the old spring mounts/rails removed the mudguards and mounts.
So I hacked together some temporary mounts that doubled as stringers to support the plywood on the way home from the shop.

Bought the ply.

Total outlay so far for trailer, registration and transfer fee, new spring mounts, new wheels, 6 sheets of plywood, fuel, etc is $1200

Ply is labelled as "MIN 450 kg/m3"
Lets say it's 500kg/m3 on average.
Then those 6 sheets weigh something like 140 kg.
Plus the 150 kg or so that the chassis will weigh with the new wheels, I'm up around 290 kg. before I add the roof sheets and if I use all the ply I just bought. Might end up at 400-450kg with the mattress (40kg?), water (30kg)and battery (30 kg) the time i'm finished. I'd be happy with that I think.

[MickinOz]

Any Aussies out there got a suggestion for a polyurethane product for The Mix?
Oil based exterior polyurethane seems a bit rare.
Local hardware shop choices seem to be Cabot's at $50/L or ............nothing

[edgeau]

I use Bondall Marine varnish - it is UV stabalised. Thins with Turps

https://www.bunnings.com.au/bondall-1l- ... h_p1521655

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[tony.latham]

Oil based exterior polyurethane seems a bit rare.

I can't speak for your side of the big blue, but over here "the mix" isn't normally (if ever?) done with an exterior poly. Just oil-based polyurethane. If you need to UV proof it, add a couple of coats of spar varnish over it.





Tony

[MickinOz]

Thanks Tony. Obviously I missed that little detail about not needing exterior grade.
I suppose if the only difference is the UV protection it isn't necessary if you are going to PMF it or paint it.
Definitely expands the range of possibilities this side of the big blue.

Edge: Thanks heaps, I was aware of Bondcrete and stuff like that but I had no idea that there were other products. Doesn't come up when I search the Bunnings site for polyurethane.

Looking very promising, and the price per litre is much the same whether you buy 1l or 4 L, so I guess I can just buy as much as I need for a change. How refreshing.
Did you thin it and soak the timber a la the mix?

[frosty]

I am enjoying the read and info mate.

hope to start mine soon.

cheers

[cheaterparts]

A comment on trailer wheels:
Just about every car we saw here in Oz when we still had a car making industry had hub centred wheels. That is, the middle hole in the wheel was a snug fit on the hub, so the wheel was centred by the hub and in theory the hub took a lot of the weight and the studs main job was to hold the wheel onto the hub.
It's what I'm used to and expect.
So I was a bit left-footed when I found this seems to not be the case these days. In the trailer world, it seems to have disappeared altogether. No one does it.
Everything I could find to buy, including well known international brands, seems to be lug-centred. i.e. the taper on the nuts and the tapered holes on the wheel are used to centre it.
No one seems to offer a combination where the wheel is a snug fit on the hub.
I mentioned this to my mate and he said it's the norm now on cars.
Even when the wheel is hub centred, it is often centred with a removable plastic or alloy ring, definitely not loadbearing.

I think the wheels you bought are a fairly normal trailer wheel and designed to fit all bearing setups - the centre hole is normally a fairly close fit to an axle using Parallel bearings ( 1.6 tonne rated here in OZ ) the front of the hub has to be big enough to take the larger bearing as they run both the large bearing of a ford bearing set ( 35 mm ID )

[MickinOz]

Thanks mate.
I definitely need to stop second guessing myself.
The ply I bought is slash pine with A Bond, complying with the AS/NZS 2269 standard for structural ply.
So naturally, I stress at the idea of pine plywood.
Until I find out most marine ply these days is A Bond hoop pine. According to the internet (which is never wrong ) hoop pine has about the same durability.
Allegedly, one of the differences is that marine ply has no voids. Until you read a few posts where people have cut into voids.

Damn it, gunna go with it.
Will cut out the floor pieces and saturate an off-cut with mix and leave it to set. If that comes up aces, the job's on.

A note on worrying. In a different era I had an out door public address system of the sort used for events like motocross, car racing etc.
I used to worry like buggery the night before a big event, inventing all sorts of ways to get around any imaginable problem.
This stood me in good stead, I always had a plan B.
The only logical conclusion? A certain amount of worrying is actually a good thing.

[MickinOz]

I dreamed the three 17mm sheets would form the floor and provide off-cuts for smaller parts.
The 15mm would form the walls.
Until I unloaded the trailer and realised the 17mm sheets had one face that might arguably be B grade rather than C and one 15mm sheet was pretty ordinary. Now it will be the other way round.

[edgeau]

Did you thin it and soak the timber a la the mix?

Yes I thinned it as per the mix (much more than the directions on the can) and brushed on ever stronger coats.

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