paulbrook

Seam sealer and the like should be polyurethane not silicone. You are right about gasket sealer though as that seems to be silicone based, but applied in small quantities. What happens with using silicone (the household type) is that tiny flecks and smears disrupt paint applied later

Brilliant and a great inspiration. Thanks for sharing!

The other thing about silicone is that paint hates it, and any slight silicone residue will result in "fish eyes" in the paintwork which can be a PITA. If you do use silicone or suspect there could be some about then wipe down the primer coat with silicone removing panel wipe (or even diluted household bleach) before putting gloss paint on.

His latest bit of work for me, machining the AC flywheel to take a starter ring gear, can be seen here. Before doing it he had to adapt both the chuck and the gap block.

Astonishingly ten FNs made it to UK as part of a pre-lend lease deal. Sadly now all cut up (although I used to own a survivor). Its frame number is still etched on my memory - FN1C1181

The more I see it the more tempted I am.... Whereabouts is it?

Interesting. Is that a Diamond T cab on the back?

One thing's for sure - Dan's welds don't leak! He is a structural design engineer in the nuclear industry and really knows his stuff but also has a small company that do "impossible" engineering. So I think that the tank will be good for a hundred years or so. He did talk me through casting a new tank, and there is plenty that can go wrong with that too! Here is another of his masterpieces

Now that is a thing of beauty..

Wow that looks excellent and never mind what anyone else says well worth restoring! If you can get it to a seaport and into a container I could give it a home!!

All up I would guess about $3-400 for all this (like I say, I have not seen the bill yet!) but that involved all the set-up work. Now he has the files digitally I guess that subsequent repair sections would be much cheaper. We have done some work on another project (a WW2 Armored car) that is very rare. There is a similar one being restored by a group over on your side of the pond and we have been able to share all sorts of digital files which they can take to their local laser cutters, machine shop or foundry. I say take - they can email the files with the click of a mouse and the finished parts simply arrive in the post. That's what happens when you get some of these clever young folks involved

We were going to try that, but actually what we have now is the original but (virtually invisibly) repaired. On these old trucks much is so simple to make, like the cab, but over the years I have tended to want to try and use an original replacement or repair the original part if I can, even if that is harder than just, say, cutting a new cab side out of a sheet of metal. That said, sometimes only new will do!

I did not know you had a Packard. I have been dallying around buying a WW1 5t Packard from a guy I know in France for a few years now - but never plucked up the courage (besides I have too many projects as it is!). The 3d stuff that Dan is specialising in is a kind of half-way house: rather than try and print the final part he is printing the pattern from which a part can be cast, which makes it really cost effective. Many foundries can now print patterns, so if we want something casting out of some exotiv material we can simply email the file for the pattern to the foundry and they can then do a one off at little more than the cost of actually casting the thing.

Dan has not sent me the bill yet! But the way he went about making the patterns was fascinating. First, he chopped out the rotten buts then set them up on a rotating table before scanning them with a laser scanner to form a 3d digital image. He then "cleaned up" the image to create a digital 3d image of what the repair part should look like. He then scaled it to account for the shrinkage when the part was cast before 3d printing the pattern using a foam that burns away as the molten metal is poured in. A simple sand mould casting was then pretty easy. He tells me that one of the advantages of the "lost" foam is that it tends to smooth out the casting surface - much more like die casting. I will ask him how long it took.

After quite a while since I first started with this project where other priorities got in the way, I have now picked up the pace on my AC restoration and thought that others might be interested if I posted a picture or two along the way. I have loads of pictures of progress so far hosted on a site called "photobucket": a link to the first album of pictures of my AC is here http://s484.photobucket.com/user/RustyTrucks/library/Mack as advertised but you should be able to navigate around my particular bit of Photobucket for lots and lots more. Just nearing completion is the restoration of the radiator which had suffered greatly from electrolytic corrosion of the aluminium top tank. after a little investigation my son Dan decided to get radical and designed, 3d printed the patterns and cast 2 new sections that he then welded into place to restore the strength and integrity of the tank. All the pictures can be seen here http://s484.photobucket.com/user/RustyTrucks/library/Mack AC Restoration 2019 but I have added a "before" "during" and "after" to this post just to give a flavour. Next job is to machine down the flywheel a bit, fit a starter ring and convert the engine to electric start - more to follow!