Rich27028 said:
i see no problems with what the welder did -
Sorry, but as an AWS-certified welder, I'm gonna have to disagree. And I can't believe they charged 100 dollars for that. The welds look OK, but the overall job is mediocre. I'm sorry if that pisses anyone off, but, I've been doing this for a long time, and I've seen a lot of welders come and go in my area, they 'go' because they do work like this.
As bassboy already mentioned, any decent welding and fabrication shop would have made a piece of U-shaped channel to place over that rib, after welding the existing cracks in the rib itself. The channel should be made to cover the full length of the rib, and if it's a slight v-hull that also requires a notch, bend, and weld to make it follow that angle.
Then, the new channel would be stitch welded every 12 inches or so, with at least a 6-8 inch long stitch welds, on a staggered pattern, that is, on the opposite side of the channel, you put a weld where there isn't one on the other side. You have to remember that in addition to being 1/3 the weight of steel, aluminum also has 1/3 the strength, and this must be taken into consideration for all joint design, fit-up, and welding.
should be plenty strong -
my feelings are you are trying to out think this - welding is as strong or stronger than the org metal and he also added a extra piece - i would not worry about it -
It is true that the weld itself is stronger than the base metal, this is also something that has to be taken into consideration. I've seen welds that looked pretty, peel right off aluminum like it was a bead of caulk, and that was from improper joint design, improper penetration, and/or overall lack of consideration of forces being applied to the joint. Again, aluminum is 1/3 the strength of steel, so this means that whatever you would do with steel, you have to do it 3 times better, thicker, and stronger with aluminum.
and yes a floor would stiffen the boat a lot -
Now THAT, I do agree with! A floor, as long as it is attached to the ribs, will act as an additional structural member, which ties everything together and stiffens it up. Also, putting foam under the floor panels will dampen vibration and noise, as well as giving it some added strength, as well as added buoyancy in the event of getting swamped.
Now, as far as putting a rib in front of that existing rib, you could do it with a piece of aluminum channel, rectangular or square tube, or angle.
Use at least 1/8" thickness, by at least 1 & 1/2". 16 ga is going to be too flimsy. Preferably do it with the tubing, as it gives more strength, being a closed-shape design. The good news is that aluminum is very easy to work with, you can cut it with a regular circular saw, just as easy as cutting lumber. So, make a good, close fit on that rib, then use some SS carriage bolts, from the underside of the boat, with 5200 sealant.
