"The superstructure is all-aluminum, so work on the underbody is the main concern; the topsides won't fall apart faster than the restoration"[ IMG]http://i559.photobucket.com/albums/ss37/dj82501/001.jpg[/IMG]
It seems the superstructure is not all aluminum at least not the foundation on this erra of Barth. I do seem to recall seeing a early factory assy. pic. that looked like they were all aluminum. Does anybody know if this is true, and if so what year did the switch over the foundation from aluminum to steel ? Foundation meaning the floor structure.

I'm sorry I doubled up a picture, I am still trying to get the hang of this, I will have to get my son to help me learn how to add the arrows and comments to help describe what I am trying to show. I'm sorry I doubled up a picture, I am still trying to get the hang of this, I will have to get my son to help me learn how to add the arrows and comments to help describe what I am trying to show.

With the whether forecast they are predicting,It doesn't look likely the 27' will be ready for INDY, My racing buddies are tiring to convince me that there's one last Hara left in this one, if we go for it it ought to be one interesting trip.

AFAIK, the chassis shipped by GM to Barth, called the P30, consisted of engine, frame rails made of steel, running gear, etc. Barth attached a superstructure of 1" steel tubing to it to support the lower steel compartments housing generator, LP tank, batteries and the like. From the floor line up, the structure was always structural aluminum tubing and channels. The skin is mostly corrugated or flat aluminum, riveted to the aluminum tubing. Some Barths had fiberglass end caps. The aluminum below the floor line was attached to the steel tubing by rivets and separated from the tubing by some sort of material to prevent corrosion due to dissimilar metals touching one another. This whole steel tubing assembly was subject to the effects of water and salt like any other steel structure. It's unfortunate that Barth didn't make the 1" tubing out of structural aluminum as well as the storage compartments. I'm sure others can explain this whole arrangement better than I can. My 85 has some 1" steel tubing that I'm replacing. Your pics show the doors on the compartments in place. Is the problem that the compartments behind those doors are essentially gone?