bertram31.com

Does anyone know what grade of aluminum Bertram used for the window frames?

I do not but am interested as well as I need to grind out some corrosion and would like to weld some material back in rather than using JB Weld.
If we don't find an answer here (never happens) I'll let you know the settings I use to blow holes in the aluminum as I try to weld.
Best Stephan

I do not know what Bertram used.

Marine aluminum is a 5000 series, today expect to see 5086 used.
Marine filler rod is 5356.

As its above waterline and going to be sealed anyway, 4043 filler works too.


I have cleaned, ground and welded up windshield frames before. It has to be one of the worst welding jobs...so lousy I think I'd rather build me a new frame than weld up the one I have that NEEDS attention. A job I have been putting off almost as long as I've owned the boat...26 years.

So what is SO lousy about welding the frames... Corrosion and welding do not get along. Clean grind and cut away till nice solid, add some heat and watch what looked like perfect solid aluminum open up, smoking and bubble away. Cut it back, clean, wire wheel and grind back to clean and start adding heat again hoping your back far enough in good metal to add filler. Now do that in every position known to man in tight channels. Each little pinhole and pit becomes a job, each little job done opens another pit, another hole.
Overlay so no blemish is left is an effort in futility, I'd work on frame an hour or so each morning till it got too hot. At the end of each day I'd grind, machine, prep n position for the next morning. Job seemed like a neverending project. In the end, they came out about 95%. That was better than the customer expected, not as good as I'd have liked.

I see this as my winter project...one reason I am reluctant to pull the boat. I have to get this started...which also means doing the curved window panels.

Ugh...

Well Then!
Better to run from a fight then have to retreat. No lightning holes for me.
Has anybody worked with this stuff or have a recommendation other than welding to repair the aluminum?



Continuing my motto of putty and paint makes a guy look like what he ain't.
Stephan

Same problem but from a different angle.

Corrosion...you have to get it all out before you slap paint or putty over. If you do not, the corrosion continues causing the paint to bubble n blister or the putty to be pushed up and away ruining your once-perfect finish.

Steal rust is usually easier to deal with as it all sits on the surface slowly working its way down. Grind till clean and your done. My experience with aluminum in a saltwater environment is some of the issues can be under the surface. A superficial pinhole with a crevasse under.

That said, it usually looks good for a while. If you get it all, that awhile can be a long while, I did on my pilasters, the first two times it looked good a whole season or so, third time and it still looks good 15 years later. I ground and glass beaded each time before an alum prime and paint...I'm guessing the last year I got down far enough.

Thanks for this thread, it is timely for me as I need to attack the Baron's pitted windshield frame. It sounds like I am going to get my fabricator to build me a replica---out of stainless!