T-16 S/N 5399 T.D. 97377 Restoration

[horsa]

We added up other known item weights and worked backwards from what the total vehicle was supposed to weigh. Estimated the stripped hull at 3500 pounds. The gantry the dip place had was rated for two tons but they said it could probably hold a little more but didn't know it's true safety margin.

They didn't have a scale when it came time to testing things out but said it was easily within their normal weight limits based on having moved other vehicles around with their forklift and the gantry so I guess our initial estimates were pretty close.

You'll notice in the shots that I took the bogie assembly mounting brackets off the lower hull. This was to further lighten it as well as to allow fast drainage of the chemicals due to their weight and added time it would have taken to lower and raise the hull if the liquid couldn't get in and out easier.

[Philliphastings]

Hello David and thanks for the pics. Chemically dipping large assemblies is of course the first choice of restoration techniques but even when I lived right in Sydney, near to a place that could do it (I was building jeeps back then) it was just too costly to have done. I wish I could afford to have the Scout hull dipped as even the sandblaster i hoped to have organised locally seems to have come to nought.

I am likely to have to carry my hull on a car trailer on a 600km round trip to Perth for sandblasting when the time comes...

Congratulations once again on a first class restoration by the way - simply awesome !

Cheers

Phill

[Lynn Eades]

I would suggest a preliminary chemical treatment prior to the sand blasting.
The reason for this line of thought, is that mine has rusted badly in the floor, even though it was white blasted, cleaned, primed and painted, all on a fine dry day. I believe the armour plate forms large holes inside,from tiny pin holes at the surface, that the blasting process has no effect on.

[horsa]

The chemical dipping process can be expensive since they apparently charge by weight and not by surface area. So anything armor will cost quite a bit more than sheet metal panels or small parts and brackets. That could well be part of the reason why they did my hull for such a cheap price as they saw pictures and we talked it up and made a deal before they ever got back to asking how much it all weighed. If the price had been what they want to charge others for the work now, I wouldn't have used the service due to my budget at the time.

But knowing what I do now that it's done and I've seen the results, I think I would still dip it if I were to start another project. The chemicals can clean out areas that sand blasting wouldn't be able to reach.

In terms of what Lynn said about the floor on a sand blasted carrier rusting after the fact, I was worried about that on mine before I found the chemical dip place. Part of my rusty floor looked flat and smooth while other areas were deeply pitted. I tested it with a hammer and was able to break off some of the flat areas and found the wavy pitted metal underneath. So I ended up getting my air chisel and went over the entire floor several times. That left my entire floor wavy and pitted but it was at least solid metal. I figured a sand blaster would only be able to work the exposed metal so didn't want to have a problem later on. Odds are the chemical dipping would have gotten to most of the lower layer on its own but I still would have had problems I think since I'd have primed the upper surface metal that might have broken off later. So I'd recommend anyone planning either process should go over the floor really well before hand. You might tear off a lot of metal but it's not good metal. That way any needed repairs can be done before you have everything striped and primed.

I'm not sure why the original floor was as I found it. It really seemed like a thin sheet of metal had been laid over the thicker armor hull down there at first. And water got between them and rotted one underneath and weakened the upper layer from beneath it. Must be part of the old laminated armor process where the outer edges are hardened and the inside is left mild.

[Philliphastings]

Very interesting posts Lynn and David. It has got me thinking. Years ago when I first recovered 2 pounder Carrier 6146 from rural NSW I filled up the hull with warm water and molasses and left it to work for a week or two. I seem to remember that the result was pretty good but not perfect.

I am thinking of trying citric acid in the scout carrier for two reasons:

1/ we use it almost daily at the Military museum and so far has provided some fantastic stripping results and at a very moderate cost (as well as environmentally and persaonnaly safe)

2/ Surprisingly enough the interior of the Scout hull is actually very good - in parts where the original finish of the armour can be seen it appears almost like new - it's just that almost everything else has a thick layer of rust and many of the original bolts have become compromised.

The outer and especially the upper armour is in good condition save for a thick rust encrustation and I might consider the old trusty wire wheel (or a few of them) if the citric acid works well enough. It might sound very slow and labour intensive but when you are 300km's from the nearest industrialised city you have to make-do

Wish me luck

Cheers

Phill

[Lynn Eades]

There are many products on the market that are based on phosphoric acid.
you paint the stuff on and it kills the rust. I'd do that, and then blast it.
Forgive me for preaching here, but what you have in the scout is unique, and needs a good job done of her. No half measures. If you do it well, you will be proud of her, and she will be worth a pretty penny.

[horsa]

Yep, I live by the wire wheel mounted on a 4” angle grinder as well. Even tried sections of the hull that way but found there were too many places it couldn’t get into and they were usually the most in need. Plus like I’d mentioned before, my floor was deeply pitted after air chiseling the top crust off and the wire wheel wasn’t very effective getting into the moguls without excessive pressure being applied which reduces the life of the wire wheel or wire cup, plus the motor on the grinder.

I experimented with phosphoric acid when trying to figure out a good way to get my tracks freed up. They had been rolled and stored for a long time before I got them and required a breaker bar to force unroll them due to heavy rust. I broke them into sections and made my own chemical bath to test two sections. Results were visible after a few days but it was going to take a lot of work to free up each link since they would need to be moved back and forth a bit and then soaked again. This would need to be repeated over and over until the section was good again.

After getting the two test sections done, I looked back at the stack of waiting sections and decided to seek out a more cost effective solution. The molasses trick is an old one that most people have had good results with. But I couldn’t find an affordable source for bulk molasses here in Texas, even checking with the cattle feed and supply stores. Basically it was by the gallon like the phosphoric acid and wasn’t cheap. Space and a way to deal with the mess was also a concern for me working in a residential neighborhood. The ideal thing would have been a large galvanized metal horse trough for placing both tracks in with the chemicals. Then they could be worked on and off while flipping them around inside.