7 Skin Removal

[IamScotticus]

Is it possible to remove the whole set of body pannels as one piece?

[Croc]

No.  They are in 3 pieces.  Two side skins and one rear basket.  Join is under rear wheel arch.  

[IamScotticus]

Five pieces.

It would be tricky to not disturb the filler in the join at the cockpit elbow.

Perhaps torching off that fillet and forgetting about it is the way forward?  I can find a skilled metal man later.  Or eventually do it myself. 

 

 

Edited May 23 by IamScotticus

[EdWills]

Hi Scott.

I was able to accomplish this on my original Lotus Seven Series 3 many years ago when the car suffered damage after I was forced to drive over a very raised up manhole cover (I was boxed in, and unfortunately too late to see it!). The bottom floor skin, among other items on the car, was badly damaged (torn), but the chassis was not bent. I stripped the car completely, turned the bare chassis upside down, and drilled out all of the rivets on the bottom of the chassis.  I then turned it right way up, and removed the rest of the rivets from the panels.  I was able to carefully pry up the side panels starting at the bottom, along with the rear panel by gently uncurling it starting at the bottom.  With help, I was then able to peal the complete body - consisting of both sides and rear still attached - by lifting it upwards from the tubular chassis.  I braced the entire body work using 1" x 2" pieces of wood (using screws in the rivet holes) to completely brace the structure so that it would not buckle or crease whenever I moved it.  I was able to drill 1/2 inch dia. holes at the very front of the top and bottom 1 inch square side tubes to release most of the drilled out rivets from the chassis. I lifted the chassis up high at the rear and shook it from side to side a bit to release most of the rivets trapped inside the tubes.  Arch and Universal Radiator did not tend to block off any of the main tubes when constructing their chassis. A vacuum cleaner also helped suck out any loose debris and the rest of the rivets.  The holes drilled at the front to release the drilled out rivets can be (braze or fusion) welded closed when rebuilding.  To replace the bodywork when all of the repairs have been completed, Cleco skin pins are ideal for 5/32" holes.  If you drill a rivet out and the hole becomes too large, you may have to go to a 3/16" rivet for replacement. When drilling out 5/32 inch dia. rivets, use a slightly smaller drill bit than 5/32 if possible, by using a numbered drill bit. This may help prevent the rivet hole from becoming larger than 5/32 inches.  It seems that Monel replacement rivets in 3 lengths may be harder to obtain these days. Try Hanson Rivet in the U.S. or Rivetwise in the U.K. Hope this helps if you are still considering removing the ally body completely. Good luck. Will

[IamScotticus]

Interested in this.

On my 7,  the left side front panel had been replaced by a previous owner but the elbow wasnt welded before being sold.

I already have a set of skins that will not hold together as one piece.  I ask for the benefit of future readers, and I may still be able to remove these without buckling with proper bracing.

 

I would love to re-skin the whole car, but it's hard to justify as the damage is only few square inches of area. But its in a difficult location next to the lower frame tubes, both sides, requiring skin removal for access.  Repair could be attempted from the outside but I don't want the torching to compromise the rail coating in that area that is susceptible to water ingress. (Yes, in Houston this is an amphibious swamp buggy)

 

(Don't drive a fully loaded 7 onto a U-Haul car trailer)

Edited May 24 by IamScotticus

[EdWills]

Hi Scott.  I was under the impression that your Caterham body was still in one piece, but I see from your pics that you have at least one non-welded join in the bodywork.  I also should have clarified that the 'original' Series 2 and 3 chassis did not have extra triangulation that Caterham/Arch later added in the rear of the car to add some strength. They also riveted some extra paneling to the bracing (just behind the seat back) that would require rivet removal and 'uncurling' .. I do not know how much extra triangulation, and therefore riveted body panel(s) your chassis has.  I see that you were just asking for the benefit of future readers, but of course there have been many chassis variations over the years, and perhaps removing a body in one piece may not be practical?  I also removed a set of body panels from a Caterham/Arch chassis, and it was much easier to cut the panels either side at the weld just below the bracket that holds the hood sticks (by the shock tower).  A tad easier to hide this join if you do not intend to have it welded back as it was in the first place.  Will

[IamScotticus]

Even if I were able to get the elbow joins off, held together with clecos, the join at the hood stick bracket looks like it would't survive the handling.  

 

I wonder a few things about this join...are they welds or fillers?

Is the material a low temperature high nickel alloy?  

I have read the Cat used Calor Bronzecraft No.3 (no longer available) with the gas jet flux braze welding process.

A replacement or substitute is SifBronze No.2 and SifBronze 101 (thanks, Bill)

Is this something within the scope of a low skill yahoo with a propane torch?  Or is yahoo going to need to learn to weld?

I don't see how these alloys are torched on the frame without damaging the frame coating.

If I ever do a frame restoration, Im not a fan of powered coat (the reason for a restoration) I will be painting with something like a high temperature chassis epoxy paint.  I don't know if that can withstand torching in.

[EdWills]

Hi Scott.  I apologize if I am reading this incorrectly, but it appears that you may be referring to the alloy (aluminum) bodywork, and sorry if I am getting this wrong, but you cannot nickel bronze this material. It has to be welded with similar aluminum rod.  Arch do it (according to the various pics in Lotus Seven books) by joining the alloy at the top by the damper/shock tower, and Tig welding the material together on the outside of the frame, then carefully grinding it down to make it smooth. My knowledge of frame construction engineered by Caterham is iffy.  The new owners of Caterham some years ago, stopped using Arch to construct the chassis and instead turned it over to a company called  'Cages'.  Cages turned to Mig welding to construct the chassis (there is/was a Youtube video by Caterham showing the construction stages of their newer version of the 7). I do not know of course if your chassis was made this way, or before by Arch?  

I took a couple of revision welding courses before I even attempted to touch my chassis to attach some brackets that Arch had for some unknown reason omitted.  The instructor allowed me to just practice nickel bronze braze welding instead of arc welding - which I wasn't really interested in.  I do have a gas fluxer, but these are now very expensive, and the flux is likewise.  I would not call myself a competent braze welder, but my nickel bronze brazed joints don't look too messy.  Practice a lot on scrap tubes, but make sure that they are very clean, and get all the oil or grease off using MEK.  You can use already fluxed rods (try Allstate), but my instructor told me that you can scrape off some of the flux, as they plaster it on, and not all of it is required thus making clean up easier.  I can send you the article, but maybe a competent local welder who is familiar with braze/bronze welding could do the job for you.  I would certainly take my chassis to a local shop where a gent around my age - with tons of experience  in braze welding - could do the job for me, but I already had the equipment from long ago, and I save money doing it myself without having to lug the chassis back and forth every time (I don't own a truck).  Let me know if you meant something different re the chassis and body joining methods. Will

[IamScotticus]

My interest is in the repair and patching the aluminum.

I did not know if the bodywork used the fluxer or not.  Good info.

 

Edited June 1 by IamScotticus

[EdWills]

Hi Scott.

Just an aside. According to Carroll Smith in his book "Prepare to Win", if you have been using a jet fluxer on an oxy/acetylene set-up (where the liquid flux stored in a pressure bottle is picked up in the acetylene gas and carried in the acetylene hose line to the torch), if you then wish to weld aluminum, it may be easier to change the acetylene hose to a different one as it takes some time/use to clear the hose line of flux. The flux from the jet fluxer is not compatible with aluminum welding.  Mr. Smith advises that the torch and fittings will clear themselves of the jet flux fairly quickly. Will