Southern GT Chassis #54 Build - The What Have I Done Chronicles!!

#1
Hi all
So finally the build has started, took delivery of the chassis last week, spent a while unpacking all the panels, checking bits, putting back whats not needed yet and off I go on the journey so many of you guys have done. Mind you some great support thus far from SGT and Mick plus I am lucky to it seems be close to many great resources like Frank and Paul.
Getting a set of stands off Paul (PaulBav) now his 40 is road legal (well almost!!) this Saturday but at present its the floor pan being sorted, may be being a bit OCD filing to make it fit 100% spot on for a part that few apart from the odd run over squirrel will ever see but devil in the detail, as my mentor said, "If its worth doing lad do it properly".
So workshop ready, did treat myself to a new Teng toolkit, have amassed a few tools over the years but its only when you look hard you see many are old, worn out and past it, much like I feel most mornings. Think I got carried away mind, went for the big monster one, still will see me out so worth every penny.
Also have a bit of light relief should I get stressed, pinball restoration always been a hobby along with jukeboxes, although that has to go as well, going to be morphed into a GT40 part of some sort, gearbox maybe?
So I'll post as much as I can, ask questions, have a laugh, get some input and thoroughly enjoy the whole process.
First question though, not sure why the image upload rotates my images through 90 degrees? Is it because they are not square? That ain't bad, question 1 and its not even about the 40 :)
Cheers
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#2
Shaun;

Your project looks very nice. I've always wondered (but never asked) what aluminum alloys and what rivets other people use on their builds?

For my underside stressed panel I used 0.060" 7075-T6 and 451 5/32" CherryMax blind rivets. The panel is finished with a 2-part epoxy zinc chromate primer.

Regards, Neil Tucson, AZ
451 Rivets.jpg
 
#3
That damned impressive Neil, hope you have an air riveter!! Mine has rivets to the outside frame and centre tunnel and is riveted and bonded to the chassis, should start some actual fixing this evening.
 
#4
Hi Shaun,

Welcome. Seems you’ve picked one of the best there. SGT has a terrific reputation.
What part of the UK are you in?

Simon
 
#5
Shaun;

Yes, I did not pull those 451 rivets by hand. I have an FSI air/hydraulic riveter. The CherryMax rivets are 15-7PH stem with a monel body. These are FAR too strong for manual installation- even Popeye could not pull them with a hand tool.

Regards, Neil Tucson, AZ
FSI Gun.jpg
 
#6
Hi Simon, I am in Sussex, just outside Uckfield, village called Fletching, known mainly for its great pub!!
Neil that is a tidy piece of kit!! I have been told even those that can be done by hand the number we have to do its well worth investing in an air powered one, as you say not enough spinach in the world !!
 
#8
Simon;

You'll need the big Gespia PowerBird Gold or Pro. The smaller electric rivet guns won't touch high-strength aircraft rivets.

Regards, Neil Tucson, AZ
 
#10
Shaun, a pal of mine used to live in Cross in hand many moons ago ( in Max Walls old house) so know the area a bit. Nice. If I’m running the Gtd around that way I’ll let you know and take you for a drive if you’re up for it? I’m in Upminster, just through the dartford tunnel.
Simon
 
#11
Shaun;

Yes, I did not pull those 451 rivets by hand. I have an FSI air/hydraulic riveter. The CherryMax rivets are 15-7PH stem with a monel body. These are FAR too strong for manual installation- even Popeye could not pull them with a hand tool.

Regards, Neil Tucson, AZ View attachment 92952
The things I like about the FSI PT-100 riveter are that it has a pull of 4,000 lbs and only weighs 30 ounces. Its light weight is a welcome feature when I'm pulling so many rivets.

Regards, Neil Tucson, AZ
 
#12
Simon yep please do always here most of the time would be great to catch up and have a chat and a spin, I know Cross in Hand well we lived very close to it for quite a few years..Max Wall eh that's a blast from the past :)
 
#13
Ok so quick update, lots of looking and delaying the first step, checking then checking again and sleeves up and off we go. Floor pan now on and riveted, will spin it over tomorrow onto my new stands (Cheers Paul) and start panelling the upper body working my way through the panels now all sitting round the workshop walls.
So far so good, only tips I would have for this early stage are don't use too much bonding adhesive, I was forewarned on this as its very liquid, well not the first tube as that was like solid Dunlop rubber, turned out it was 2 years past its sell by date!! Also put all the rivets in loose before firing them home (and use a rivet gun!!) as otherwise again due to the liquidity of the adhesive it will squirt out the rivet holes. Nothing that a bit of Cellulose Thinners wont tidy though whilst wet.
First job when spun will be riveting the centre tunnel (I bonded it and used a lot of weights to hold it right down) then cut out my nice new floor pan to fit the lowered sections as I am a tall bugger. Still gives me some alloy for the odd brackets.
 
#14
Ok quick update, floor fitted, cut for the lowered floor pans which was somewhat nerve-racking, was not totally happy with the gap as one side sits atop the centre tunnel flange so I got a roll of hard rubber strip 1.5mm thick and added that to the 3 sides and it looks and sits a lot better, just need some slightly longer rivets as the 10mm ones are not long enough really so have gone 14mm.
Have laid out the jigsaw panel pieces, thanks Paul for the build log you did, it made life so much easier, I have a few that I cannot find locations for but Paul is on the case.
Most seem to fit ok, just need some fettling so have got hold of a band saw with a really high tpi to trim any, will be useful thought this stage I am sure.
Going to dry fit everything with Cleco's before I actually pop rivet so just bought another 100 Cleco's, will resemble a hedgehog by the end of it!!
Thank the lord for an air rivet gun, mind you by air hose has perished and its only a couple of years old, its one on a self winding drum, was a good make or so I thought...Chinese tat it would seem.
So back to the pop pop pop of rivets and drilling, did get a smaller 10.8v Makita drill with hex drill bits as its so much easier for drilling the alloy panels and my other best purchase was a rivet spacer, that is just so useful, spot on rivet spacing.
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Cheers
 
#15
Speaking of a "hedgehog of Clecos".... A 6Al4V titanium panel then
Cleco Panel.jpg
riveted to a steel tube sub-frame with CherryMax rivets.

Regards, Neil Tucson, AZ
 
#17
Shaun, Clecos are like closet space, hard drive capacity, and horsepower-- a little is good, more is better, and too much is just enough.

Regards, Neil Tucson, AZ
 
#20
Shaun;

One thing I've noticed is that many riveted panels don't take full advantage of the strength of the materials being joined. If the joint is only decorative or ornamental, that's one thing, but if it is a structural joint, it needs to be done with more than just a handful of hardware-store pop rivets spaced haphazardly. There are very useful standards and publications that deal with this subject and more. You can find "MIL-HDBK-5H" on the internet; Chapter 8 deals with rivet strength in various materials. NASA's MSFC-STD-156 also is useful as is the Experimental Aircraft Association's website:

https://www.eaa.org/en/eaa/aviation...ion/aircraft-hardware-what-you-need-to-know-2

For structures, why not use a high strength aluminum alloy instead of other alloys? 2024-T3 or 7075-T6 has tensile strength higher than mild steel but you need high strength rivets to develop a full-strength joint. Blind rivets of A286, Monel, etc are really strong so they are difficult to pull and require a pneumatic/hydraulic rivet gun. Another disafdvantage is that the dissimilar metals can create electrolytic corrosion but this can be minimized by using a two-part epoxy zinc chromate primer on the aluminum panel after drilling the rivet holes. I like to seal the faying (overlapping) surfaces with RTV before Clecoing the joint together. Epoxy also works well but makes the panel harder to repair.

The disadvantages of the high strength aluminum alloys are that they are VERY difficult to bend and require a large bending radius even if you can find a bending brake that is strong enough. I use these alloys for flat panels so it's not a problem. Corrosion susceptibility is higher than alloys such as 5052 or 6061. They are also NOT weldable. 6061-T6 is a good all-around medium strength alloy that is weldable and can be formed with generous radii.

This is not directed at you or meant as a criticism of anyone here, it is just a general observation and suggestion on how to improve the stuff we build.

I'll get off my soapbox now... :)

Regards, Neil Tucson, AZ
 
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