Wednesday, November 11, 2009

Shop Time

Today I started welding up the frame cross member and support plate. I Klecko'd the support plate to the trailer skin, then positioned the cross member between the main frame rails.

Once everything was in place, I tack welded the cross member to the frame, and then tack welded the support plate to the cross member. That made sure everything was exactly where I wanted it. After that, it was a simple matter of grinding the tack welds off the cross member and bringing the cross member / plate into the shop for welding up solid.

My shop is currently, how you say, a mess. Interior skins are piled here, belly pan wraps are piled there, j-channel strewn about with a liberal sprinkling of interior window frame trim to add to the chaos. Add in your normal household fix-up projects, and you have a real dump. What the heck. I'm building things in there, not getting the space ready for a Better Homes and Gardens photo shoot. A clean shop is a shop that's not being used to it fullest potential.

Look at that stack of dimes. My little 110v MIG does a fine job of melting the metal. I could have welded 5 or 6 one inch welds along the seams and it would have been plenty stong enough, but I was having so much fun I decided to weld the entire seam up. I was talking to my friend Steve a while back about this little project (ByamCaravanner on AirForums), and he made a simple comment. He said something like "Metal does wierd things when you weld it". Well, Steve, you were right. The support plate developed a nice bit of warp from all the heat. Hopefully not enough to bother anything, but I'll find out when I go to mount it on the trailer. If I have to, I'll ditch my work, start over, and chaulk it up to experience. I know I can build this piece better, and better is the enemy of good enough.

Tuesday, November 10, 2009

Frame Fixin'

I'm working toward having my trailer campable by next June for the Wally Byam Birthday Bash in Central NY. I decided I better get moving or I'll never make it in time. So, today I got my butt in gear and got to work. This is where I left off after I cut out the rotten frame cross member and support plate.

I went to my local steel retailer, Steel Sales, in Sherburne, NY. They have a "drop room" that they'll let you poke around in. I was lucky and found a piece of 4 inch c-channel and a 24 x 12 inch piece of steel plate. Perfect! $17.00 later I was on my way. First thing I did back at the trailer was to fit a 2x4 piece of wood in where the cross member will sit so I could be sure to get the angles on the main frame rails set. The angle is 22.5 degrees, just in case anybody else is going to be doing this work.
Next, I transfered the angles from the wood onto the c-channel and cut it with the chop saw. This tool is indispensable for any kind of steel work. I cannot imagine making those cuts with a hack saw.
I was going to try to re-use the support plate, because it has so many holes that need to be aligned with the holes that are already in the skin of the trailer. Unfortunately, the plate was just too far gone. Also, I did not realize when I started that the plate actually goes all the way to the bottom of the c-channel and is not just welded along the top. In order to transfer the holes precisely, I tack welded the old plate to the new plate and used the old holes as a guide for drilling my new holes. Once I was done drilling, I carefully ground off the tack welds and I had an exact duplicate of the original plate.
Here is the almost finished piece, all mocked up. The next step will be to Klecko the plate to the skin of the Airstream, tack weld the frame cross member in place, and then once everything is lined up I'll tack weld the plate to the cross member. Then I'll grind the tack welds off the frame so I can bring the entire piece into the shop and weld it up solid. I don't want to weld it solid with it on the trailer, since I'm afraid the heat will hurt the aluminum skin. Once it's all welded solid, I'll do the final installation and welding of the new frame cross member / support plate onto the frame. Oh, I'll also cut the bottom inch of steel off the support plate that sticks down below the c-channel so it looks better. I needed a piece of steel plate that's 24 x 11, but the closest I could find in the drop room was 24 x 12. That's OK. I'll get my cutting wheel out and smile the entire time thinking of the money I save by not having Steel Sales cut me a piece to size.

Sunday, November 8, 2009

We Can Rebuild It.

This section of frame has been weighing on my mind. The weather here has been nasty, and work has been absolutely nuts dealing with the flu outbreak. Today, however, it was a beautiful day and I had some free time on my hands. Time to get at it. I spent some time building a brace to hold the shell off the trailer for when I cut away the support plate. Much to my surprise, the shell actually lifted up about an inch rather than coming down. The support beam I put in place fell once the shell lifted up, barely missing hitting a window. The Airstream gods were watching over me, I guess.

Bad, bad rot. It's amazing what the tin worm can do.Tuesday I'll head to Steel Sales and buy replacement steel and begin fabrication. I have a few other small holes and weak areas to fix on the frame in other spots, too. I should be able to get that all fixed up pretty easily, then I'll POR-15 the frame and be ready to put down new wood for the sub-floor.