Sunday, January 6, 2013

One step forward, two steps back

Got some spare time yesterday to start welding the old '70 Ski-Doo back together. This is the first work I've done on this sled since 2008 and its sorely needed.

First I pulled the old seat tabs off. The old tabs were held on with screws which of course means each leaves behind two holes in the tunnel so step one was to weld the holes back up. This is kind of a fiddly job involving a small rosette weld. With that done I welded on the two front tabs:

Today I went out to test fit the seat and ensure the spacing was correct, I'd only tack welded the tabs in case my spacing was off. I rapidly discovered that although my spacing seems good the board I used for the seat base is too thick and the tabs won't fit it. I used 1/2" plywood which I thought was the same as what was there, apparently it was originally 1/4" ply.

If you look carefully at the picture you can see that the top of the tab just barely pokes through the ply. Part of the problem is that the wood is thick, the other part is that there are stiffening ribs that run perpendicular to the tunnel which raises the wood a little. This raising is actually a good thing because it means that the bottom of the wood has a chance to dry and not rot out as quickly. To help that I've polyurethaned the wood within an inch of its life and just before I install the seat I'll wax the wood which should help it shed water even better.
With the seat not fitting I didn't know what the problem was and still didn't know if my spacing was any good so I removed the million staples that hold the seat base to the seat so I could look. In reality I shouldn't have attached the base to the foam before making sure the tabs fit right...

So my options are to bend the tabs until the seat base fits right, go with a thinner seat base, or put the tabs on spacers. I measured and played and found some 1/8" strap steel in my garage that will make the perfect spacer. So I'll weld the tabs to a scrap of the 1/8" steel and weld that to the tunnel. Further investigation reveals I had the tabs 1/4" too far forward anyway so its a good thing I didn't finish weld the tabs in.

Before anybody says anything, yes the paint I put on the tabs is a terrible match, I had some Cub Cadet yellow that is a much better match but I can't find the stuff so thats just Rustoleum to keep rust at bay. You'll also notice the tunnel is very rusty. I'm thinking this summer to strip the whole chassis down to nothing and have it sandblasted and repainted. That might require the tunnel top be replaced but we'll see...

No comments: