Thread: Ute tray sheet

Slowly making progress on my tray build.
Planning on using 2mm zinc for the deck.
Question this time around is, will I be able to get the 1830 x 1760 out of one sheet, or will I need to have a join? Perhaps a special order for my local metal supplier, or is it no big deal?
If a join will be needed, I'll need to figure out where it will be before I go and order the sheet.

Short answer no you won’t get enough material from a 1200x2400 sheet, you’re about .8 sqm short for your dimensions.
You’ll probably have to ring around for availability, in theory larger sheets that will cover the size you need are available, in practice it’s another matter as there may be minimum buy in from the supplier to retailer. Regardless of whether you buy in a larger sheet or get two smaller sheets you’re in for a lot of offcut, to the point I’d be giving consideration to buying from a cut to measure supplier and buying two pieces cut to wherever you need the join. My obsession with symmetry says it needs to be in the middle, and over a beam.

Thanks, it wasn't so much about whether I can get that much out of a standard sheet, as whether I can get it in one piece, i.e. is there a larger standard sheet than 1200 wide. I'll be annoyed to have to have a join but I guess two smaller pieces will be easier to handle.

Sheet comes in 1200 or 1500 generally (most places will be able to supply 1200x2400 or 1500x3000 relatively easily), coil can be had wider up to 3600 but you’ll need to find somewhere using it that’s prepared to sell you a piece.

2400x1200 sheet of zinc in 2mm is around $270 1500x3000 adds another $80-100 to the bill (Galv is around the same price).
Cutting and folding varies wildly, one place I use charges $5/cut another has a minimum charge of $30

I’d look at 2.5mm tread plate, the join will be less noticeable when it’s painted. Also quite a bit stronger than flat sheet.

All the commercially made steel trays I’ve had have had joins in the floor.

Thanks for that info, just what I needed. I'll work on a joint on the middle on a cross member. Hopefully the place I usually use won't want to charge me for a full sheet for each piece, I use sheet metal so rarely the offcuts will sit in my shed for years.

You can always add an additional lighter cross member to join on if the existing ones really aren’t working out.
A piece of angle would be fine I reckon as you really only need a strap to weld onto.

When I did my big trailer I used checker plate and joined on a cross member. The first join I made the mistake of fitting the sheets too close together and they buckled up slightly when I welded them together.
The next join I left about 5mm gap between the 2 sheets so when I welded I could stitch weld the edge to the crossmember, and the matching weld on the other sheet filled the gap.
I’m sure there’s better/more conventional ways to do it but that worked well for me.
However you do it just don’t butt the ends of the sheets tightly before welding!!

Steve

Weld the sheet flat on the bench and planish the welds, stitch the sheet to the tray frame from underneath.

Originally Posted by racingtadpole

Weld the sheet flat on the bench and planish the welds, stitch the sheet to the tray frame from underneath.

You could do that, but I wouldn't go that way myself. I build ute and truck trays commercially and we just join on a crossmember, but always leave 3mm gap between sheets and stitch the sheets to the crossmembers BEFORE welding the joins. Turn your welder down and you will get a flush weld and no rippling.
Normally you'd use checker plate, but if the OP really wants flat sheet, then 3mm black sheet is readily available in 1830 width X 6000 length sheets from the likes of Bluescope and they will usually cut to length in 1000 increments.

I ordered the sheet today in two (slightly uneven) halves. They're going to charge me for two full sheets (1200x2400) so I'll have to come up with some project for the offcuts. Already have one in mind.
I'm not a fan of chequerplate other than for steps and the like, absolutely hate shovelling or sweeping off it, a smooth surface suits my needs.
And this may raise some eyebrows- I plan to sikaflex the deck sheet to the frame members.

Originally Posted by Karl Robbers

You could do that, but I wouldn't go that way myself. I build ute and truck trays commercially and we just join on a crossmember, but always leave 3mm gap between sheets and stitch the sheets to the crossmembers BEFORE welding the joins. Turn your welder down and you will get a flush weld and no rippling.
Normally you'd use checker plate, but if the OP really wants flat sheet, then 3mm black sheet is readily available in 1830 width X 6000 length sheets from the likes of Bluescope and they will usually cut to length in 1000 increments.

Just to clarify Karl, do you stitch the sheets to the crossmember from underneath before welding the join - or do you stitch in the join itself?

Steve

Originally Posted by Pete O

I ordered the sheet today in two (slightly uneven) halves. They're going to charge me for two full sheets (1200x2400) so I'll have to come up with some project for the offcuts. Already have one in mind.
I'm not a fan of chequerplate other than for steps and the like, absolutely hate shovelling or sweeping off it, a smooth surface suits my needs.
And this may raise some eyebrows- I plan to sikaflex the deck sheet to the frame members.

Nothing wrong with a good bit of bondage Pete
With my relatively limited fab skills, if I was going that way I think I'd join the sheets OFF a crossmember and use a piece of 3mm flat as a backing strap for the butt join to reduce the blow through and swearing...

Steve

Originally Posted by OxxAndBert

Just to clarify Karl, do you stitch the sheets to the crossmember from underneath before welding the join - or do you stitch in the join itself?

Steve

When laying out your sheet/s, you tack them to the side coaming rails and wherever there is a join, you do the same but also tack the sheets together (which usually tacks them to the crossmember lightly in any case) every 150 to 200mm, then stitch from underneath, with one side of the crossmember being adequate unless it is a crossmember with a join on it, in which case stitch both sides of the crossmember so you catch both sheets.
It is very important to do the stitching on the underside before welding the joins so you don't get rippling of the sheets.

Originally Posted by Pete O

I ordered the sheet today in two (slightly uneven) halves. They're going to charge me for two full sheets (1200x2400) so I'll have to come up with some project for the offcuts. Already have one in mind.
I'm not a fan of chequerplate other than for steps and the like, absolutely hate shovelling or sweeping off it, a smooth surface suits my needs.
And this may raise some eyebrows- I plan to sikaflex the deck sheet to the frame members.

I have much respect for Sikaflex.
Have you considered not welding the joint in the sheet? If you're going to Sikaflex the sheets down to the crossmembers, you could just leave a 3-5mm gap and seal that as well.
To get Sikaflex to work properly as an adhesive, and boy will it work, you need to use double sided tape to create an air gap that allows the Sika to cure properly.

Originally Posted by Karl Robbers

I have much respect for Sikaflex.
Have you considered not welding the joint in the sheet? If you're going to Sikaflex the sheets down to the crossmembers, you could just leave a 3-5mm gap and seal that as well.
To get Sikaflex to work properly as an adhesive, and boy will it work, you need to use double sided tape to create an air gap that allows the Sika to cure properly.

Yes, having had to get the sheet in two halves, I don't intend to weld them together, I will -as you suggest- leave a small gap and fill that with the sikaflex.
I'm not sure what you mean by using tape? Strips of tape alongside the sikaflex? Small bits of tape to act as spacers?

Originally Posted by Pete O

Yes, having had to get the sheet in two halves, I don't intend to weld them together, I will -as you suggest- leave a small gap and fill that with the sikaflex.
I'm not sure what you mean by using tape? Strips of tape alongside the sikaflex? Small bits of tape to act as spacers?

When bonding the wall sheets on a truck van body, we would run 10 or 12mm mm double side tape full length on every upright, typically offset to one side (30X30 members in most cases, with 50X25 wherever a sheet join occurs) and then a bead of Sikaflex run next to the tape before the sheet is put into place. The double sided tape we buy in rolls that are probably 3-350mm diameter, not the piddling little rolls that Bunnings sell. Given that your ute tray sheet will be horizontal, rather than vertical like a van body wall, you could definitely get away with using less tape. It won't overly matter how you go about it, provided to use sufficient tape to achieve a consistent stand off distance, thus maintaining a flat floor and the tape also serves the dual duty of holding the sheet/s from moving until the Sikafkex cures fully.
When removing sheets from van bodies that require repair (crash damage typically) the bond is such that we will use a forklift and a chain to pull the sheet from the frame, such is the bond strength. You should be able to get away with a 50mm strip, then a 150mm gap or thereabouts, just make sure that you test fit everything dry and have a competent offsider help you place the sheets, as you really only get one go at placing them accurately. Wax and Grease remover is the weapon of choice for smoothing the sealant and for clean up. To smooth the sealant, get a rag dripping wet with Wax and Grease remover and run along the seam that you want to smooth and you will find that you are left with a smooth and consistent bead of sealant that looks like it grew there.
If you can get it, Bostic polyurethane adhesive and sealant is superior to the Sika products in this application, with Selleys polyurethane (available from Bunnings) being my second choice. Both are cheaper than the Sika products into the bargain.