Captinjohn,this welding rod you are talking about is a zinc based alloy much like white metal.Zinc will bond to aluminum much in the same way that a bronze brazing rod will adhere to carbon steel.It does have a fairly low melting temperature and melts at a much lower temperature than the base metal aluminum which you are trying to work with.Compared to real aluminum brazing using aluminum brazing rods and flux,this zinc based rod makes for some very brittle joints.Vibrations from the engine could be a real concern here.Most commercially made engine mufflers like those from Bisson and Slimline are aluminum brazed and are very strong.This method doesn't disfigure the end product as much as T.I.G would as there is no welding bead to contend with when finished.The end result is a much smoother finish to the end product and less time in the final finish stages(no grinding)so you end up with a far nicer looking product when finished.After these mufflers are aluminum brazed and finished the joints flow together so well,you can hardly tell where they were joined.It takes a lot of practise to become this good and to fully understand the process.Blow outs are very common doing your first few pieces.The funny thing about working with aluminum unlike steel is that it doesn't change colour before it turns into a molten mass.One second it's a solid mass,next second,it's a puddle on the floor[:@].

To date,I don't think I've met one single person who has had any luck with this product that you,ve mentioned.It is sold under a variety of names and one that comes to mind up here is "miracle rod".Yeah,they sure make it look easy at those trade shows.I was flatly turned down by the demonstrator one time at a trade show when I asked her if I could come up and try out her wonderful product in front of the other people that were there watching also to see just how easy it was to use.So easy,a kid could use it.....yeah right.A good friend of mine who works as a T.I.G welder gave me some of this welding rod to try out after he couldn't get it to work. I experimented with it and it didn't work worth a dam for me either.I tried repairing a hole in a coke can just like they do at the trade shows and followed procedure to the letter.The molten rod would just roll right off the can no matter what I did.I experimented with different temperatures and it just didn't make a difference.

For the record,it does make a difference as to what type of brush you use to clean the surface prior to welding or brazing aluminum.It has to be a stainless steel brush and not a carbon steel based brush.The carbon in regular steels will imbed in the aluminum and contaminate the weld area preventing any chance of proper fusion/adhesion.The wire brush is used to remove the oxide film coating which is found on all aluminum to allow for proper adhesion to the base metal.The area's to be joined must be free of any oxides prior to the welding being completed.The oxides will try to start forming again on the freshly exposed aluminum surface immediately after being wire brushed so it is imperative that the welding be done as soon as possible after cleaning.Don't leave it too long or else you'll have to start all over again.When brazing with an aluminum rod,a special aluminum flux powder is used to help break up and clean off the surface oxides.T.I.G uses a very high frequency wave to break up the surface oxides on the molten weld pool area allowing the welding rod to flowed into it.Hope this helps you some Captinjohn.