Has anyone tried brazing aluminum cylinder heads with a Berzomatic Al3 or a similar rod? I’m not suggesting it’s use for repairing cracks but for repairing electrolysis damage around water passages and for severe pitting. I recently picked up some edmunds heads that look great on the show surface but not the go surface. I’ve had good luck with JB weld for minor repairs but I’ve often wondered whether brazing would be a suitable alternative.
I have seen a demonstration on the product your asking about where the salesman is welding a soda can. It sure looks easy however I tried to use the stuff to do a similar job to what your asking about . I found it impossible to get it to work on thick material especially where there is corrosion that's impossible to clean. Maybe someone else has had success on thick stuff. Ronnieroadster
A guy I used to work for would have welded them up, dressed up the holes and slapped them on the big belt sander to finish the surface off. The man spent half of his work day just about every day welding up damaged aluminum heads in the cylinder head rebuild shop he owned. I've got a twin set to those for my flathead but my water jackets don't have much if any corrosion. I don't have a shot of the back sides handy though.
Unless they are exceptionally rare - and a head that actually improves performance - I don't know that it worth the bother. I know shops that will not even attempt it due to the amount of shitty metal that has to be chased, porosity etc. It ends up costing more than the heads are worth. Unless as I say...
I realize the heads don’t offer much of a performance boost but I’d still like to preserve them so I suppose they fall into the category of not much to lose by trying. My thought was to still treat the damaged areas as if I were going to TIG weld them, by grinding back to fresh metal (well as fresh as you can get in an old mystery alloy aluminum casting). In the event it doesn’t flow well, theoretically, I’ll have caused less damage to the casting and left myself the option of resorting to the hot rodder’s duct tape, JB Weld or Devcon.
Ronnieroadster was it your impression that the lack of success was due to an inability to get enough heat into the area to get it to flow or due to oxides bubbling up and interfering with the wetting? As I mentioned in my last post, my thinking is to first do no harm. I’m trying to leave myself all possible options. I don’t want want to jump to Tig welding and have a blow out that turns these into another wall hanging in my shop. By God I’m going to resurrect these one way or another.
IMO you are going to spend way more fixing than worth. A good alum welder can weld those but chasing the dirt/contamination which is there when welding is a bitch, then remachine and handwork as needed will be costly, they will make nice wall art in your garage.
If that were me seeing it is on the water jacket I would go with JB Weld. Good clean up then if possible drill some little holes in the sloping bit, not going right through to give a better grip for the JB weld. Think this would be the most economical solution.
What I have found is two problems the heat required to allow wetting and the oxides from corrosion. I have as posted by brading used JB weld epoxy on damaged water holes in similar condition to these heads. I would the epoxy route its easy cost effective and works with proper preparation. Ronnieroadster
I have done a couple of sets of heads that had similar damage with a high temperature epoxy intended for use on aluminum. It worked out just fine. I sand-blasted the areas in question and applied the epoxy. I gave it a day to harden and then evened the surface with a large file. Think about it, even if the epoxy comes loose (which it won't), where's it gonna go on a properly torqued head and a quality gasket? I have always heard that trying to weld old unknown aluminum alloys is a crap shoot at best. I have never tried it, but I have tried Muggy-Weld and the "stuff at the fair" on a number of projects. It worked well on a Corvette headlight bezel once, but it usually produces unsatisfactory results. In my opinion, if there is no structural problems, epoxy is the way to go. Now, as to the Edmunds heads. I have two pair on engines right now and would use them any time I could. Edmunds heads have a feature that most other aftermarket (and stock) heads don't. The spark plugs are relocated just enough so that they clear the exhaust valves which allows the use of extended tip plugs. I believe this is a significant advantage. If those were mine, I'd give 'em the epoxy treatment, and then check the clearances over the piston dome. I'd have them milled (the usual case) or enlarge the combustion chamber in the head to bring the clearance over the piston to .055 to .060. This optimizes the "squish" for the most efficient combustion. I think you will find that doing all of this will produce a noticeable increase in performance over stock heads. It did for me. Oh yeah, they look good too.
Can you bake them to have impurities and such out-gassed first? A shop repaired a cracked bolt hole on an Al intake I had in the late 70’s, I recall them saying that was what they were going to do.
Sounds like the consensus is to stick with the high temperature epoxy. They will definitely look cooler in the engine bay then on the wall of my garage. How much of a performance boost do you suppose you get over the stock heads? I’ve seen a few posts where people say they have even used high temp epoxy in the combustion chamber. Not sure I’d go that far but it’s an interesting thought. Now I’ve got to find a set of Edmund’s for the engine in my profile picture.
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