32ft x 10.5ft to become 42ft x 16ft.

Adding to 1968 aluminum displacement hull. Will be done in stages between fishing seasons. Adding to the sides this year and length next. I'm just a fisherman with a welding machine. Can anyone tell me how much heigher she will float with 532 sq. ft. added to sides this year? Material weight will be around 2700 pounds. Added sides bottom shape will be flate and sides straight.

 

Fisherman
Its not so trivial, there's a lot of things to consider here, because you are increasing the vessels size and displacement so too you need to increase the scantlings of your frames stringers and plate.
Basically though if your added material is 2700 lbs then if your increased displacement is 43 1/2 cubic feet she'll float the same, if it displaces less she'll float lower and vice versa.
More than that I cannot say I'm sorry unless we knew all the vital statistics of your vessel.

Might be best to stick to sheltered water, or get the help of a local proffessional.

 

Have a lot to learn.

Yes, I found the weight of one sq. foot of water to be 62 lb.s , without a detailed study, all I have come up with is that she will float about the same with this first stage. I can move some equipment to correct for minor difference. If any one knows of a true proffessional in Central Alaska I would be very interested in contacting them. We have boat builders in the area and I will have one working with me welding the wet hull parts.
Thanks for the conformation that she will float the same. Protected waters is not an option, she has be be ready to fish between June 20 to Aug. 9 every year.

 

Alaska Fisherman

Are you living on an S shape inlet, approx 5 nm from Salamatov?
Just curious what you are fishing? Chatka?

 

I live on Cook Inlet and I drift fish for Salmon.