Honda CRX Forum banner
1 - 4 of 4 Posts

· Registered
1,818 Posts
Discussion Starter · #1 ·
Looking for some advice on putting some fresh metal in a rusted rocker.

Here's a (big) pic of the area about midway through the cleanup:

First, there's dimple in the lower part about 1/2" from the end on the right side (just to the right of the jack mount). Am I right that that is a weep hole to allow water out? It was full of crap--I think that's it's function, but the gaps between the metal sheets were pretty gnarly with light rust, so it's hard to tell.

Second, I know I've got more clean up to do, but I'd like a sanity check on my plan. Right now, I'm focussing on the rocker itself--I know the quarter panel above has significant problems, but I'm going to delay that until I get more experience, and try to use civic hatch wheel arch replacements for that part of the project. So part of this involves not going too high up the panel, since most of that will come out later (certainly everything above the main crease, possibly everything down to my patch.

*Finish cleanup of rust spots, and treat the innards with rust remover while I've got it open. Fortunately, I can get to the top of both the inner and outet panels up to the main crease--it's tight, but doable.

*Sand to bare metal for the joints, and then use some weld through primer on the metal.

*I've got two pieces of galvinized sheet to go into the gaps. I've read up on procs for welding galvinized, so I'm planning on using a snokel tube and filter to keep clean of fumes (that, or I'll break out the scuba tank). The upper piece will go on the outside of the inner panel, and the lower piece on the inside of the outer panel. Both pieces have about 1/2" of overlap right now, and the pieces fit pretty nicely.

*I'm planning on using drilling holes and making plug welds about 1/2" inch apart. I'm thinking this instead of a butt weld all the way around because I haven't held a torch in 20 years and I'll be upside down (yes, I've got a torch instead of a mig, but I've got some experience with gas and none with electricity, and yes, I've got practice pieces to play with first). I figure I need to offset from the spot welds for the jack point.

*I've ordered some silver allow solder from muggyweld, it's rated at 65K psi, figure to fill the gaps between the plug welds with that, for additional strength and to stop water penetration. To get the rod in above the lower seam of the outer piece, I'll have to drill a hole, but I think I've got that visualized pretty well. I need to do a test of this idea to make sure the solder will flow well with whatever remnants of primer are left, but that's the plan right now. This solder is horribly expensive, but the flux is water soluble so you can get rid of that easily (this stuff is suitable for applications involving food service), and a lap joint with it should be close to butt weld strength.

*After that, I figure to spray in rust encapsulating primer over the inner surfaces, and follow that with an eastwood product that's similar to waxoyl (basically, an oily wax for coating the inner parts of panels.

*Then the usual bondo/sanding/paint.

Am I crazy?

(DOH! Stupid question, I'm restoring a 19 year old car in my copious spare time).

Does this seem like a reasonable plan? What am I missing?


· Registered
1,818 Posts
Discussion Starter · #3 ·
Its me DUB said:
Sorry can't give any input on this...but document as much as you can to help us out. You sound like you know what you're doing though!

Not really, but I've been trying to do research and strike a good balance between what I would do if I had vast resources and [email protected] sK!llz and what I can manage. As a friend of mine says, I have to be thorough because I'm not that good....

I'm taking lots of pics and making notes--if nothing else, I'm likely to have three more sides to do. I've found some good links for quarter replacements, but not much on rockers. Figure I need to go the extra mile on the rear end of the rocker since it's close to the jack point.

· Registered
1,818 Posts
Discussion Starter · #4 ·
Well, I can say without fear of contradiction that today in practicing with the new torch that I have produced what can only be described as the most abysmal series of butt ugly butt welds, lousy laps, and awful looking spots with lots of blow throughs, curling sheet metal, pops, sparks, slag, not to mention small fires. Burned my fingers and cut myself.

It was a great afternoon. I love fire. Fire good.

After a couple hours, started getting the hang of it again--got the flame size about right for the thinness of the metal, the preheating and the timing. Starting makiing some reasonable spots decent puddle patterns in lap welds. Then spent a good bit of time relearning how to fill in blowthrough holes. With a little luck, I'll get the rocker panel replacement sections in by late tomorrow....

· Registered
1,818 Posts
Discussion Starter · #6 ·
Ragnaarok said:
practice makes perfect! keep it up...
Practice makes a mess:

Ok, here's what I did. Keep in mind, I have no experience with this. I'm pretty happy with how it came out and I learned a lot doing it. Structurally, I think it's much better than before the repair, and cosmetically, it's not that great, but it's covered by plastic anyhow. And I think I've got a good shot at staving off the rust at this particular point for a few years. If anyone thinks this is worth a howto, let me know and I'll polish it a bit and submit it.

Here's the starting point:

As you can see in the pics, I cut out the most of the rusted sections in both the inner and outer rocker panels with a dremel. The rust continues all around the wheel well, but I'm lleaving the bulk of it in until I can more experience--later I'll cut out the wheel well edge completely and replace, most likely with a civic hatch piece.

Here are the old sections I cut out (actually, I cut out more than this, these were just from the first pass).

For replacement metal, I cut up some galivinzed sheet. I used galvinized because I had that already. To shape the body line of the outer panel I beat the metal sheet against a 1x2" board. What I really is a sturdy table with some inserts like anvil swedges (I think that's the term) of different shapes and sizes).

The angle on the right side of the left piece was so I could fit this piece above the outer panel, but eventually I had to punt on that idea (more on that later).

A picture of the fitting of the inner panel. I used rivets to fix the inner panel, as it turned out I should have used 1 rivet per inch. The notches along the lower edge were cut out so that the surface of the inner panel would be close to the height of the metal left from the spot welds holding the jack point to the pan. In trimming away old metal I did not want to go to deeply at those spot welds for fear of weakening the jack point. And I wanted the outer panel to fuse smoothly along the entire length, so the goal was to present a pretty even surface.

In addition to the rivets, I used a silver solder from muggy weld to weld this piece in place. Silver solder is expensive, but not prone to corrosion and is relatively strong (much stronger than lead solder). The melting point iis about 1300 degrees, so it's cooler than a steel weld, but stilll a lot of heat. This particular solder uses a water soluble flux--one reason I went with it was I wanted to be able to get rid of the flux easily.

To reach the back side of this piece, I put the rod in through both the hole in the wheel well (the one with the plastic stopper--that plastic stopper, btw, was pretty loose on my 88, so I think that's a good spot to keep an eye on for water penetration), and through the cut out higher on the rocker where I cut out a section that was rusted through.

Here's what it looked like after a partial cleanup. As you can see, I had some metal distortion along the upper edge in the middle--when I do the other side, I'll use more rivets to help control that. I also used a heat block putty to keep the heat along the seams.

My original plan was to flange the patch piece for the outer panel, and mount that inside the outer panel. When I got to this point, tho, I realized that there was no way to access the back of this piece once it was installed. I didn't want the rust to come back, so I really wanted to have a way of getting to the back of the panel.

So, I punted, and decided to put the panel on the outside of the rocker. To get it more or less flush, I had to flange the outer panel inward a bit. The flanger pliers I have wouldn't fit between the two panels, so I used a piece of wood behind the outer panel for support and used a small hammer to beat in the outer edge a bit, and then flattened the flange flat with a small channel lock.

I also punted on the idea of using the silver solder on the upper parts of the outer panel--I figured I'd make a mess of things and burn off all of the primer and zinc. And I'd rented a video on panel repair that showed replacing a section with eastwood's panel adhesive, so I figured I'd give that a try. But I did want to use the silver solder on the lower edge, for the long term strength. So the plan became:

* Clamp the piece on the lower edge, and drill holes for rivets around the sides and upper edge.
* Put some tack welds on the lower edge
* Solder the length of the lower edge.
* Clean up everything on the back side of the panel, prime everything on the back.
* Then use rivets/adhesive to lock fasten the sides and upper edge.

Here's the view of the panel clamped in place just after welding/soldering the lower edge, from above--this approach gave me the working space to get the rod on the upper side of the lower seam:

Here's the view from below just after the second pass--the grey stuff is the heat block. I did three passes--the first with some small tack welds along the lower edge, then cleaned that up, then two passes with the silver solder (the second pass soldering about 1" each, spaced out to keep the heat buildup down, the third pass to fill in the gaps). After the third pass, I gently heated the length of the lower edge to relax the metal, and let it cool slowly. I had a couple of small burn throughs, but over all I was pretty happy with it. I was also careful to keep the weep hole open.

After this step:
* I cleaned up the inside and outside of the patches
* Ground down the excess metal
* Wirebrushed all the metal (including the pan where the undercoat was burned off).
* Used an acid wash on the bare metal.
* Swabbed the inside of the rocker as far as I could reach with a bit of a sock on a coat hanger dipped in rust encapsulating primer (figured that couldn't hurt while I had it open)
* Put a coat of the same primer on the inside of the outer panel and the outside and inside of the inner panel, and used enough on the lower edge to fill any gaps left in the solder joints. I kept the outer edge of the outer patch unpainted since the adhesive is designed for bare metal.
*Mixed up a batch of the adhesive and applied it, then put the rivets in. The adhesive is supposedly waterproof, so I lapped it over the painted part of the panel a bit.

This last step was pretty intense--I had _not_ checked to make sure the rivets would all fit, and two wouldn't (since the panels were too close together). One rivet didn't cinch down, so I had to drill/cut it out in addition to drilling some more holes around the epoxy. I am convinced that a painter's five way knife is the single most useful brute force tool one can have--I used the blade to cut the rivet in half, and the hook to pull the piece out from between the panels.

Fortunately, this stuff cleans up with lacquer thinner if you get to it before it hardens (which takes about 30 minutes).

Here's what it looked like after the first pass:

After it hardened, I make a quick pass with some 60 grit to sand down the high spots, and applied a second coat to fill in the voids:

I then sanded the whole patch pretty smooth. I did not try to get it completely smooth since I'll be (hopefully) painting the entire car later. I figured I'd leave this pretty much unfinished so I can check for problems later, and if it looks good after a few months or more, then do some move agressive sanding to smooth it all out, and skin it with bondo.

After sanding, I applied some more acid wash to the bare metal, and primed it with 4 light coats:

To finish up, I sprayed rubberized undercoating on the back side, the pan around the jack point, and in the lower part of the wheel well, and put a piece of aluminum tape over the hole I cut in the upper part of the rocker visible in the last picture (that will get fixed when I replace the wheel well part of the quarter panel.

The adhesive is pretty impressive stuff, but it's not cheap. There's a product called smoothon that I think I'll use instead when I get to the quarters--it's a milspec product used for field repairs. Also, 3M has a panel adhesive that sounds interesting. Eastwood claims you don't need to leave the rivets in if you don't want them, but if you can get to the back side to get them painted, I don't see why you'd need to remove them. The epoxy sets up pretty hard, but has some flex to it, so it seems it should work well for panel applications.

Anyway, that's all for this miniproject for now....
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.