Rust repair before paint, The quest for solid metal in the driver side Long - 73 narrow body/4 rebuild thread Options

[930cabman]

AT LAST, good metal

Like finding water in the desert (not really)

[Montreal914]

Next step, cleaning up the surface rust in the upper long.

So this is the situation now.




More specifically, I am looking at treating the surface rust in the upward portion to start with. Here! (Note that this picture was taken before I removed the Inside-inner lower portion shown in previous post.)




Inspired by @"Alain V." , I found online people using powdered citric acid mixed with water to dissolve rust. (IMG:style_emoticons/default/idea.gif) Looking at the amount of fluid I will need to soak some of these large parts, I decided to try it out! (IMG:style_emoticons/default/stirthepot.gif) Dissolve 2 cups of citric acid with water in a medium pan at medium heat. On the side, fill a tote with 3-4 gallons of water. When powder is dissolved, carefully poor concentrated acid into tote. Now you have a cheap mix of rust dissolving solution. (IMG:style_emoticons/default/sunglasses.gif)

After trying overnight with a piece I had, I was pleasantly surprise of how efficient this was. Then I used Alain's setup, got a larger tote, a $20 submersible pump, a hose, and a sprinkler head I had laying around.

This is the setup, spraying the citric acid in the long. I started from the top and gradually moved the spray head down.




As you can see the upper portion of the long is now nice and gray, 50 year old metal renewed! Arrow is pointing at the fan spray pattern.




And a last one because this is so cool! (IMG:style_emoticons/default/biggrin.gif)




After a few days of progressively moving the spray head from top to bottom, I used another tote with a mix of water and baking soda and flushed the whole area for 1/2 day to neutralize the acid. @Mayne , Next, I plan on using some Eastwood rust encapsulation that I will brush inside. Then, after having closed back the long, I will use the Eastwood inner chassis spray with the flexible hose and nozzle, or spray cavity wax.


With all of this done, we can now see what was hiding below these bumps (tip of the iceberg) I had noticed a while back. Here is the refresher picture of these bumps:



And here is what was under that bumpy inner layer... (IMG:style_emoticons/default/rolleyes.gif)




So I now know what will need to be cut out of the lower part of the inner long. Time to look at the donor parts I actually have to see what can be used.

First step, dismantling the factory assembly by drilling every spot weld and separating every part... (IMG:style_emoticons/default/smash.gif)

After splitting the outer from the inner of the donor parts a few weeks ago, here is what have. To assess if the metal both of the inside-inner and inside-outer can be used, I need to dismantle this whole assembly. So the engine mount needs to come off and the inside suspension console too. Hopefully I can achieve this while saving these parts. I don't think I will need them, but maybe someone here will.




And here is the engine mount removed. There is some rust (IMG:style_emoticons/default/dry.gif) but it is too early to fully assess at this point. As you can see the separation work of the inner suspension console is well on its way.




And here is the inner long free of all attached components. I am interested in this portion circled in red.




That being said, I am actually interested in both the outside-inner (seen here ^^^) and the inside-inner (seen below). So I will need to separate the two onion layers... Here we can see what I am looking at using. Fingers crossed for the metal to be in good shape at the interface. As we can see I have stated to separate the two layers.




More to come, stay tuned! (IMG:style_emoticons/default/smash.gif)

[Alain V.]

Something really satisfying about dissolving rust and finding clean metal. Looks like you are making good progress.

[930cabman]

Very cool process (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)

[Montreal914]

Some progress to share:

Before continuing the previous post with the preparation of the repair piece for the outside-inner lower elbow area, I went on and actually cut out the bad metal, to really establish the repair piece I will need.

Here is the situation: The black sharpie line (circled in red) is where I have decided to cut and remove material.




There are a few things to consider when removing this piece. First the floor is spot welded on the underside of it, then the two vertical walls of the firewall are flanged basically on either side of the oval port. Then, at the right end, I am actually cutting half way into where the engine mount is attached (embossment). I chose this location for a couple of reasons;
1- I wanted to see the engine mount metal behind it,
2- The engine mount will serve as overlapping layer.

Based on what I have seen in removing the engine mount on my donor part, there is actually a gap between the engine mount and the embossment in the Outside-inner long metal. The plan is to add a metal layer to do an overlap on that joint. Plus the engine mount itself is an overlap.


To preserve the various metal joining to the metal I am removing, I will be cutting and grinding it away, keeping the flanges intact and ready to receive the repair piece. Here is the beginning of the process on the left side:




And here is that metal removed:




Closer view where we can see the two firewall flanges, the lower half of the engine mount (right end), obviously the floor, and the flange of the e-brake cable guide in the cabin. All of these flanges are nice and solid and will be the welding surface as I plug weld the repair piece in (minimizing upside down welds).





Now, time to prepare the repair piece. (IMG:style_emoticons/default/smash.gif)


As show, in the last post, I need to dismantle the various sections of repair parts I have, assess their condition, and make a repair piece. The donor long I got was cut to the right of the jack post, basically behind the firewall. Therefore, the repair piece will have a vertical weld roughly in the middle.


Here is the rear half of the doubled layered repair piece:




Since I will need both inner and outer layers, I had to drill all the spot welds to separate them. This works well, but unfortunately leaves one of the two pieces look like swiss cheese. (IMG:style_emoticons/default/dry.gif) We'll look into that later.



Overall, these two parts are pretty rust free and I am confident can be used as-is after getting de-rusted in citric acid. (IMG:style_emoticons/default/smile.gif)


Now looking at the front half donor parts, same process; drill the spot weld to separate the two layers.




Unfortunately, these are not as good as the rear half's. Let's see what de-rusting will reveal...




After a couple of days soaking in citric acid, here is the result. The rear end of it is a little pitted but not major, The front end (with the hole for the safety belt) is compromised in the fold and will need to be addressed (circled in red). (IMG:style_emoticons/default/dry.gif)




Most of the rest of the donor long is heavily pitted in the bottom fold except a section that I was able to cut out of. I will use this section below (black sharpie) for the repair piece.
What I am after is having the step detail of the lower part where the floor attaches to the long (red arrow).




So here is the plan; joining the retrieved good part on the right to the left half with the oval hole. Not only will this replace the heavily pitted metal, it will also take care of a lot of swiss cheese. The hole for the seatbelt will be done before joining the two.




To be continued in next post...

[Montreal914]

After carefully trimming both piece, I set them in this contraption (IMG:style_emoticons/default/wacko.gif) to join them straight. Hole for the seat belt in there now.




And the back side. Notice the copper plate to absorb the heat. A similar plate lies under the bottom surface too.




Now the two pieces are one. We can see some of the pitting on the right piece, not ideal, but not too bad. I may try to reinforce this. Here i am plugging some of the holes created by the spot weld drilling.




Moving on to attaching the rear section of the repair piece. Making progress! (IMG:style_emoticons/default/smile.gif)






Finally, three becomes one!




And after a lot of back and forth trimming, the part is now 95% ready to be installed.




Fit is almost perfect, just a little bit of fine tuning and it will be ready. (IMG:style_emoticons/default/smile.gif)




More to come soon!

[nivekdodge]

You are kickin a and taking names!!!!!

[tygaboy]

Super nice job you're doing. Great fit-up on those panels. (IMG:style_emoticons/default/wub.gif) (IMG:style_emoticons/default/pray.gif)

[930cabman]

Prior to welding new sections in place, have you been double checking the alignment of your pickup points? Looking at your jig, it appears somewhat light gauge. A quick double check will let you know all is good before new metal is secured in place.

You don't have to ask why ...........

[Montreal914]

Prior to welding new sections in place, have you been double checking the alignment of your pickup points? Looking at your jig, it appears somewhat light gauge. A quick double check will let you know all is good before new metal is secured in place.

You don't have to ask why ...........

Although it looks like I am ready to weld this in, I am not there yet. Yes I will measure everything and also temporarily reinstall the fender to check door gap.

Each little step is at slow pace where subsequent steps planning are part of every move.

Think think think, act, trying to minimize the “ah darn” moments.

[Montreal914]

Super nice job you're doing. Great fit-up on those panels. (IMG:style_emoticons/default/wub.gif) (IMG:style_emoticons/default/pray.gif)

Thank you! Coming from you (IMG:style_emoticons/default/pray.gif) I appreciate the compliment.

The file is one of my preferred tool… (IMG:style_emoticons/default/smile.gif)

[TRS63]

Taking time to get the perfect fit is key to quality work. Well done (IMG:style_emoticons/default/aktion035.gif)

Antoine

[tygaboy]

Prior to welding new sections in place, have you been double checking the alignment of your pickup points? Looking at your jig, it appears somewhat light gauge. A quick double check will let you know all is good before new metal is secured in place.

You don't have to ask why ...........

Although it looks like I am ready to weld this in, I am not there yet. Yes I will measure everything and also temporarily reinstall the fender to check door gap.

Each little step is at slow pace where subsequent steps planning are part of every move.

Think think think, act, trying to minimize the “ah darn” moments.

@TRS63 Antoine is far more concise but if I may:
HEY EVERYONE! The above bolded words are what make the ALL difference between an OK job (or worse) and the quality result @Montreal914 is achieving. Ask me how I know! Sooooo many times I've wanted to make progress and had a "that's going to be fine, it's close enough" attitude, only to complete a step and be disappointed in what I'd just done. Then I was left building off of what wasn't as good as I'd hoped.
So I want to give a big (IMG:style_emoticons/default/smilie_pokal.gif) to @Montreal914 for making this point. It's the one thing that makes the biggest difference for me. If I don't take the time to fit the material properly, I won't get the result I want. If I can't get into a (reasonably) relaxed, comfortable position, the weld isn't going to be as good.
People poke at me for doing things over and over again and this is one reason why I was doing that: my process wasn't working.
I just redid (!) the rear panel on my LS car and was sending in-process pics to @buddyv Robert. He commented about how fast I was able to crank out the project. It was because I spent a lot of up-front time thinking, planing, wondering, checking. He saw the execution, not the "pre-work". In the past I'd have just gone for it. Fun maybe, but not effective.

That said, I have a LOT left to learn - and always will. But I'm telling you, our friend here has nailed what I've come to believe are THE most important skills: patience and planning.

Great job and thanks for calling out your model for success!
OK, rant over. Back into the shop!

[Montreal914]

@tygaboy WOW! (IMG:style_emoticons/default/wub.gif)

I guess I have self set my bar high now... (IMG:style_emoticons/default/unsure.gif) I will have to keep it up because the pros are watching and will give me bad review if I don't... (IMG:style_emoticons/default/laugh.gif) (IMG:style_emoticons/default/blink.gif)

But seriously, I wouldn't be able to tackle any of this without the high quality build threads and the detailed information we can find here. (IMG:style_emoticons/default/smilie_pokal.gif) Thank you all for this generous boost, now I am fired up to get busy on the build! (IMG:style_emoticons/default/smash.gif)

[tygaboy]

@Montreal914 - One last comment about how critical I've found the patience and attitude thing and I'll stop clogging your thread. You may have seen my post about visiting the Singer factory last year:
http://www.914world.com/bbs2/index.php?sho...7&hl=Singer

For a more complete summary, read post # 8 but for thouse without patience (IMG:style_emoticons/default/happy11.gif) here's the short version, one I try and live by, about acceptable variance:
If Singer is +/- ZERO, going forward at the Red Barn, it's +/- less than yesterday!

[Montreal914]

Yikes... 11 months later... (IMG:style_emoticons/default/rolleyes.gif)

Well not much done in the last ~year on the tub rust repair but still a few updates. I took a break and focussed on other components finishing, such as many parts plating and powder coating. Shown below is a portion of it. (IMG:style_emoticons/default/smile.gif)




Also rebuilt my pedal cluster with the final help from @bdstone914 . (IMG:style_emoticons/default/smilie_pokal.gif)




Now, back to the main work, the tub... (IMG:style_emoticons/default/smash.gif) I removed the tar insulation on the cabin floor using the dry ice method. In the past I have used the heat gun and the multi-tool on another 914. I definitely prefrerred the dry ice method for a few reasons. Quick, clean, low noise, cool (great feature when working in a warm environment), efficient, other... (IMG:style_emoticons/default/sunglasses.gif)






Here you can see the frost on the underside, bringing a very pleasant cool breeze (IMG:style_emoticons/default/biggrin.gif)




Next I moved on to close these factory access points for welding. These horseshoe cut are normally covered with a round metal disk bonded in seam sealer. This is good for production cost cut, but that doesn't apply here. (IMG:style_emoticons/default/smile.gif)

[Montreal914]

Continuation for post above...

There are five of these access points in the floor, two on either side symetric in front of the seat cross member and the fifth one just below the MC port hole shown below. That one was showing some rust, so I removed some of it and made a patch. This is a difficult and unpleasant area to work on... (IMG:style_emoticons/default/headbang.gif)




And here is the patch before welding.



And the final results when everything was massaged with the finger sander (which I really find practical).






And the overall situation as of now.




Next, I want to flow some citric acid on the tunnel floor to get rid of this surface rust... (IMG:style_emoticons/default/dry.gif) these two next pictures were taken from the shifer tunnel opening looking towards the front and the back.

[Montreal914]

Next I wanted to remove some of the dents that were created on the underside of the floor over the course of the car's life. Unfortunately, many of our cars have suffered these mis-treatements where they were jacked or supported by the thin sheetmetal at one point.

I used a trick Rick Ollah ( @rick 918-S (IMG:style_emoticons/default/pray.gif) ) showed in one of his post.


Starting point (IMG:style_emoticons/default/dry.gif)






I welded a few 1/4 nuts in key areas. Here you can see the first one welded and the surface prepared for another two. Dang it is not easy to weld upside down... (IMG:style_emoticons/default/dry.gif) But the purpose is temporary so I didn't care of the welds.




Next is Rick's technique! (IMG:style_emoticons/default/sunglasses.gif) Gently pull the lever and out comes the metal!




And this is the end result. It is not perfect, but a net improvement compared to what it was.

[rick 918-S]

That worked nicely. (IMG:style_emoticons/default/thumb3d.gif)

[930cabman]

+1 with the dry ice, I recently used it to remove the floor tar, worked great. Also used it to shrink new rear wheel bearings and later hubs.

Two birds