Suggestions for disassembly of stepdown convertible top frame assembly requested

[Deleted User]

I've started working on the top for my 51 pacemaker convertible. It needs everything. I would like to try to get it done so I can drive it to San Mateo in July. Right now I am trying to disassemble the side arms of the frame that supports the cloth top. I have been using a propane torch, wd-40, lots of tapping, and lots of patience. Also I have been spraying wd-40 on a lot of the screws and pivot points, off and on, for the last 12 years or so. I have gotten all of the pivot points working. For the last few days I've been working on the screws that hold the aluminum parts of the side arms to the sheet metal brackets. Some of these screws are underneath a stainless piece. The stainless piece holds the rubber seal that goes between the side windows and the top. I have gotten the stainless piece unscrewed from the aluminum side arm. This has revealed some slot head screws that hold the sheet metal bracket to the aluminum side arm. These slot head screws are being very stubborn so far. They look quite rusted on the tops and the area surrounding them. They do still have slots in them that I have been able to put a fair amount of twisting force on without destroying the slots or breaking the heads off. Also if you notice in the last photo, their is a piece broken off of the aluminum arm. Have you guys got some suggestions? Any ideas are sure appreciated. Thanks. Rob

[Deleted User]

Try some of that freeze mist on the screws. They shrink away from the surounding metal and come loose,
Roger

MikeWA

I've had much better luck with PB Blaster than WD40 for freeing up stuff. Other possibilities are Liquid Wrench and Kroil (www dot kanolabs dot com), and supposedly the best stuff of all is a 50/50 mix of automatic transmission fluid and acetone.

I haven't heard of the freeze mist, but sounds intriguing.

As far as getting it to San Mateo, I thought the canvas "art deco" top you had at Spokane was just excellent! Kind of gave an "old west" feel to the whole thing. . .

Lee ODell

There was a recent post about penetrant comparisons. Does anyone have that link? I would like a copy. ATF/Acetone was way ahead of the others in that article but I don't recall how much better.
Lee O'Dell

[Deleted User]

Well, after I started this discussion I went back out to the shop and heated the screws about 3 more times on top and bottom and tapped and twisted with the screwdriver and I hear a faint creaking sound on one of them. I then tried my hammer impact twist screwdriver,(whatever you call the thing) and surprisingly they started to break loose. I had tried the impact screwdriver yesterday and none would budge. Within an hour or so after I went out to the shop I had all of the screws out. I would say they took 10 to 15 heat cycles with tapping and twisting with every cycle. I started sometime yesterday morning and got them loose this afternoon. I'd say took 2 hours of actual work. Hopefully I can keep my patience going and get the other apart too!

So you liked my art deco top eh Mike...lol. It was fun talking to you at the meet. Lou Cote said I had the paul bunyan thing going with my cubic foot block of wood to put the car on when I jacked it up..lol. I did use it too!

I'm going to mix up some ATF/Acetone and start trying that. I'll let you know how it goes. Im feeling really encouraged right now since I got those screws loose. We'll see how long that lasts...lol. Thanks for the suggestions. Please keep them coming. Rob

[Deleted User]

I sugested the freeze mist due to the dissimmilar metals he is dealing with. Steel csrew in allumium will have oxidzed deep in side an is not going to move. I agree all the above liqids are great ,I myself have good luck with ATF . But they all have there place,
Roger

PAULARGETYPE

ROB I TRUST YOU TOOK SOME PHOTOS OF THIS TOP COMING APART I KNOW THEY HELPED ME OUT ALOT WHEN I PUT MY PACEMAKER BACK TOGETHER

lostmind

Are you sure those parts are aluminum? I had one welded at NASA by a friend that worked there. He said it was some sort of alloy casting. They heated it in an electric oven of some sort and welded it hot. They ground it back to shape , and when it was painted you could not tell it was repaired. This was back around 1971. I\m sure methods have evolved since.

[Deleted User]

That process is correct and nessasary for most types of cast metal if you are going to arc weld it . Iron , Alluminium ,etc to keep it from cracking during the operation or cooling,
Roger

[Deleted User]

Paul, yes I took quite a few pictures. I have been looking at them. Its kind of confusing to me all of the different layers that go into the cloth top and which layers go over or under which strips of metal. Hopefully the top guy will know how to do it. I have had the framework mounted on the car several times and have all of the joints articulating so I know pretty much how it goes together.

Lostmind, I'm glad you asked that question because I think you are exactly right. It doesn't really seem exactly like aluminum. It does seem kinda soft but not as soft as aluminum. When I manage to get some of the bolts out the threads in the hole don't look like aluminum to me. I kept thinking this doesnt really look like aluminum but with my limited knowledge of metals I just didn't know what else it could be. It sounds like it is very difficult to weld.

Roger where would a guy find the freeze mist you mention. It sounds like it could be quite helpful. Rob

[Deleted User]

My brother uses it in his auto shop ,I'll get a hold of him and see what the name is,
Roger

RL Chilton

Rob-

Congratulations on getting the screws out! The screws in your pics that hold the rearmost stamped steel section to the very back casting: That is some steel-based or iron-based casting with steel screws, i.e., similar metals all three. Meaning, these screws will come out as you found out. Depends on how much time, patience and attention to detail you wish to put into it.

Further up the frame mechanism, you've got steel screws into cast aluminum. Depending on how much galvanic corrosion has occurred, it is most likely all of these screws will not come out, barring Roger's advice above, which I did not try.

I spent every day for two years soaking, heating, tapping, trying, pleading, praying to get my top mechanism apart. In the end, I got it all apart and about 85% of the screws out. A few screws had to be removed by laterally removing them, re-welding the castings and grinding back to shape. Others were, quite frankly, impossible to remove. Some were carefully drilled out, others were simply re-located as close as possible to the original mounting location. We also re-made one stamped steel section and cast 3 new parts. I'm still looking into the possibility of casting new handle-locking mechanisms, as the best pair I have are severely pitted. I've managed to repair one handle and am still trying to get the other one in shape.

Roy-
We used aluminum rod to re-weld the "aluminum" castings. If they are some alloy, then the base material, or at least the largest percentage is aluminum, I believe.

[Deleted User]

ROB - Ive been told NAPA has it ,at least his NAPA store does so if your local one does'nt they probably could get it,
Roger

[Deleted User]

Russel, thanks for all of your info. It sounds like you have really been through the wringer on your top. I have a feeling mine isn't near as bad as yours. I have gotten one of the side arm assemblies completely apart with every screw out. I did break one of the little screws that holds a little clip. The little clip is held on with two little screws that are about 3/8" apart. I think the little clip is used to hold the fastener that part of the cloth top snaps to. Now I need to find a way to weld the piece back on that is broken off of the one aluminum piece. I was doing a little online searching on how to weld cast aluminum. Most comments talked about how important cleanliness is. Some of the things they suggested were lots of scrubbing the parts in hot soapy water, baking the oil out by baking in an oven at 350 deg F for several hours, sandblasting the part, the only solvent to use is acetone. The other comment there was a lot is that it really depends on the properties of the cast aluminum you are trying to weld. Some is very hard if not impossible to weld and some isn't very hard to weld. Does this sound about right to you welder guys? I certainly don't intend to try it myself, I'll have it done.

Roger , thanks for finding out where the freeze mist can be obtained. I'll check with NAPA

RL Chilton

Rob-

I've got a welder, but not the aluminum attachment, so I had to have another fella weld one of my pieces and he didn't do any of the things you listed, and it worked great.

I'm sure the piece of the casting that you mentioned is broken off has to be the top round "doughnut" that holds the middle bow (the one with the spring attached to it). Is that correct? If so, I don't know if you would want it as an option, but I have a pair of those castings, left and right, that Bill Albright had cast many years ago. They are not drilled or tapped, which is the way you got them from Bill, as he got them from the caster.

You CAN drill out that broken off screw, but extreme care and caution and attention to detail has to be done whenever you drill out a metal screw out of a softer surrounding metal (aluminum, in this case). Start with a very small drill bit and work your way up to the pilot size. Also, clamp the part to the drill press. Don't try to use a hand-held drill. The trouble is the drill bit wants to "walk" into the surrounding softer metal, and then you have a mess.

[Deleted User]

You are exactly right Russell, the top round "doughnut" is broken off on both sides. I'm glad to hear that your guy was able to weld one of your pieces with no trouble. It sounds like the metal must be good quality that Hudson used. I also have those castings that Bill Albright sold to me. It looked to me like it would be so much work to get them ready to use that it would be better to have my broken ones welded. I feel that if I tried to get them ready myself I would probably ruin them. Unfortunately I already tried to drill out that broken off screw and made a mess of it just like you said. Fortunately it is that little one and I think I can make it work. Next time I will try to remember what you said and do it right. Thanks again for your input.
Rob

Glowplug

Rob
As an additional suggestion, aircraft maintenance constantly requires welders who have aluminum restoration skill sets. This includes identification of the type and hardness of the alloys being used so they can accomplish FAA acceptable repairs. I would hazard a GUESS that a certified aviation welder would not only identify the type of metal used in the Hudson top parts but know the recommended repair process.

[Deleted User]

I'm just thinking about this , if its out of sight could a steel plate with a ring attatched be fabricated . Then bolted to the old casting to duplicate the location of the broken ring? I know its not original but if its out of sight and strong enough - I wont tell ,
Roger

[Deleted User]

Roger, for years I have been thinking about doing the same thing you are suggesting and I do think it would work fine. Recently I found that on another severely rusted bow that I got from the owner of my convertible has the the broken rings that I have been missing. This means that I have both the pieces that fit perfectly together at the break. I'm thinking this should mean that a very good repair could be made by welding the two pieces back together. I have this same situation on both sides of the car. Last night I washed the parts in the picture for 2 cycles in the dishwasher and then baked them in the oven at 350 deg F for several hours. I think now I will sandblast them at the broken seam and then start looking for someone to weld them.
Oldfarmer, maybe I can find an aircraft welder to do the job.

Rob

Courtesy Man

A product that may be of help. Devcon Alum epoxy can be used to fill an alum hole oversize or otherwise damaged - can then be drilled and tapped - 1 lb putty at $47 so espensive, but if you can find a quality industrial product in a smaller size. How about using a soldering iron for heating smaller screws ? Just some untried ideas. Gert Kristiansen

MikeWA

Don't sandblast it- there is some danger of contaminating the soft metal with sand (or whatever media you use). Let the welder guy do the final prep- aluminum corrodes very rapidly, and has to have final cleanup just prior to welding.

I like the idea of finding an aircraft tech guy- because he HAS to know what he's doing, in order to be certified. Others may talk a better job than they do.

essexcoupe3131

As a thought, I use loctite 3805 steel epoxy glue for doing holes and re-tapping, it is also highly recommended for gluing in speedy seals for axles seals and that gets extreme heat
have also used it for repairing solid plaster work and drilled and screwed into it to hold on out side water taps that get wrenched on all the time

Mike

Courtesy Man

More suggestions on drilling out screws or bolts. If possible have the part disassembled where you can take it to the drill press - using an X Y table or best to use a milling machine where the table can be positioned exactly. Using a hand drill almost guarantees a sad ending.
Next buy three new items: a two flute end mill slightly smaller than hole, then drill with a center drill and finally buy and use a screw machine drill. There is a purpose for each.
The end mill is to give you a smooth flat surface, the center drill will not "walk" and the screw machine drill bit is short and stout. A tool supply store or internet order (Enco, for one) will do. Also use a cutting oil or kerosine , WD-40 to preservice the cutting edges if you plan on working several areas. Find an old grizzled retired machinist and bribe him - usually a 6 pack will do it and he will tell you more about machining than you want to know as he makes this
his life work to help you. Gert Kristiansen

Courtesy Man

I dont want to forget to stress the importance of clamping the offending part so the work can proceed with vigor and verbal encouragement.

russmaas

That top piece has been recasted at vintage coach About $60. Much better product strength wise, but will have to be drill and tapped.

RL Chilton

Rob-

You are better off fixing your old one. I also agree with Mike and Gert, above. Gert is a machinist by trade, and a good one.

[Deleted User]

Thanks Gert for all of the great tips for drilling out broken of screws. I am looking forward to trying your them. Fortunately I have a small milling machine to try it on.
I also like the idea of using the aluminum filled epoxy to repair the hole I already buggered up. You guys are full of good ideas. Thanks again for your input to Russell.
Rob

russmaas

Sorry, I will stop given recommendations

[Deleted User]

The fact the old one broke would tell you its not strong enough as originaly built
Roger

RL Chilton

The fact the old one broke would tell you its not strong enough as originaly built
Roger

WHAT?? These parts are over 60+ years old and most likely designed to last around 10. I think we are way ahead of the curve, personally. I think it's a plus they were cast out of aluminum and not pot metal, because if that were the case, there wouldn't be ANY salvageable parts out there.

Sorry, Rog, have to disagree with you, there.

[Deleted User]

OH thats fine , I cant tell from the photo real well how it broke anyway.
Roger ;;)