Using Solution Welding Rod For Boat Fabrication

[PX Machines]

Hi,

I am new to the forum but long time lurker, and apologize if this has been asked before.... I have a project to build a 25ft aluminum powercat and have TIG/MIG welding capability but have seen examples of "Solution welding Rod" using high tensile strength brazing. Has anyone used this method of boat fabrication, and any drawbacks to doing so?

Thanks!
Pete

[gandrfab]

The price point alone says no way.

[kmorin]

PX, G&R,

G&R, I don't know the cost of this brazing material but I can see some problems; at least in my version of welded aluminum boat building.

I use unformed plates. The bottom, for example, of a 25'er would likely be 3/16" or maybe 1/4" cut to a flat outline of the developed surface. I don't have, can't afford and might not even use if I could... forming machines to create the curvature of the hull's plate edges as joints between adjacent panels.

I pull the flat plates together until they're edge to edge (inside) and tack them every 2-3" inches along the keel, chines, sheer and other curved hull plate edges. This process requires some fairly stout pulling along the edges- pipe clamps, chain come-a-longs, (truck) nylon strap ties, electric winches..... and a good deal of sailor-like language.

Once all the tacks are in, the hull has been formed. So I could proceed to weld out the seams. BUT... I'm not sure the brazing system would give tacks of sufficient strength to hold the seams together while the next tack point was "pulled in"?

because of the speed of the arc forming, the metal melting and the tack being, well, 'tacked' the tack weld assembly allows the material to be held into the overall shape, including bulkheads and frames- while forming the entire hull. THEN, when the heat of contraction can be managed by adding welds all over the hull- seams are filled and fused.

So how will a brazing solution work for a frame tack in the middle of a 5x20' sheet without restraint? It seems like you'd have to go to some extraordinary lengths to confine the hull's plates to tacking with a brazing system due to time to heat and heat distribution vs the expansion and contraction time?

Not tried it, brazing aluminum, so I don't know from experience, just observing how I employ MIG and TIG tacks as instant fasteners to shape all the hulls I've built.

cheers,
Kevin Morin
Kenai, AK

[PX Machines]

Thanks so much for your responses! I investigated this and realized that it is too expensive and not practical. Tried to delete the post but apparently didnt work! kmorn thanks for taking the time for a well thought out response! Best, Pete