Question on Aluminum vs. Wood

[bassboy1]

Here is part of what I am taking from this;

1) .090 should be fine if built smartly but .125 is more desirable. (I will likely go .090 as I am cheap and want this to be as light as possible... I will be carrying this boat a fair bit into back country trout lakes...)

2) 1 x 1 square tubing, with 1/16 wall thickness for bracing.
- every 7 inches Horizontal
- Gussets and vertical bracing combination work well

3) Go with a pneumatic rivet gun if possible

4) Rivets
- Decking and paneling - 1/8 rivets
- Gussets and stress points - 5/32 rivets
- Framing 3/16 rivets

That is about the Gist of it. There are many more options than the 1 x 1 square with 1/16 wall for the structure. In a lot of instances that you will encounter in a jon boat build, it has the best strength/weight/etc ratio of the options. But, there will be other cases where angle may be more beneficial (combining the two eliminates the need for the corner brackets). That is really not going to be determined until you have a structure plan. I looked at 3/4, but couldn't trust it in a thin wall, and a thicker wall was heavier than the 1 x 1. Bigger stuff doesn't come with thinner walls, and rarely do you need more strength than the 1/16 in 1 inch square offers. In those few cases, the 1 x 1 1/8 (I hate fractions, why can't the US go to SI (metric)) wall will be a better choice. But, those are few and far between, and in one place where I had a large span (where the rod locker door hinge is) I used 2 pieces bolted together on top of one another to achieve the strength needed. Same weight as the 1/8 wall, but a little stronger IMHO.

 

[Macgyver]

Here is part of what I am taking from this;

1) .090 should be fine if built smartly but .125 is more desirable. (I will likely go .090 as I am cheap and want this to be as light as possible... I will be carrying this boat a fair bit into back country trout lakes...)

2) 1 x 1 square tubing, with 1/16 wall thickness for bracing.
- every 7 inches Horizontal
- Gussets and vertical bracing combination work well

3) Go with a pneumatic rivet gun if possible

4) Rivets
- Decking and paneling - 1/8 rivets
- Gussets and stress points - 5/32 rivets
- Framing 3/16 rivets

That is about the Gist of it. There are many more options than the 1 x 1 square with 1/16 wall for the structure. In a lot of instances that you will encounter in a jon boat build, it has the best strength/weight/etc ratio of the options. But, there will be other cases where angle may be more beneficial (combining the two eliminates the need for the corner brackets). That is really not going to be determined until you have a structure plan. I looked at 3/4, but couldn't trust it in a thin wall, and a thicker wall was heavier than the 1 x 1. Bigger stuff doesn't come with thinner walls, and rarely do you need more strength than the 1/16 in 1 inch square offers. In those few cases, the 1 x 1 1/8 (I hate fractions, why can't the US go to SI (metric)) wall will be a better choice. But, those are few and far between, and in one place where I had a large span (where the rod locker door hinge is) I used 2 pieces bolted together on top of one another to achieve the strength needed. Same weight as the 1/8 wall, but a little stronger IMHO.

I guess I went overkill then.....lol....In the front of my boat, with the longest span of 30" I used 1 1/4" square with a 1/8" wall and 3/16" sheet. the supports I placed 6" O/C. It ain't moving !!! :lol:

 

[shizzy77]

I just ran the math on my upcoming project for the DECK ONLY.

Approx 16' x 4' = 64sq.ft

.125 Auminum Plate = 1.76lb/sq.ft. x 64 = 112.64lbs

3/4 plywood (unsealed) = 2.13/sq.ft x 64 = 136.32lbs + 1/2 gallon of sealer = 4.25lbs = 140.57lbs.

Difference 27.93lbs.

Not as dramatic as I would have expected. For me, this decision will be based on longevity vs price, not weight.

Again, this is for the DECK ONLY.

Hope this helps someone else other than me.

I used 5/8" plywood and even my larger friends dont see any sagging when they walk on it. I would assume 5/8" to be lighter then the 3/4". Plus I wa sable to get the plywood for free from my work. they werent handing out free sheets of aluminum. for me it was a cost over longevity thing. Free with a few extra pounds and half the life was still free.

 

[cprince]

Thank again for all this golden info! Metric system is great if you were born directly into it. I was in school when we turned over here in Canada... I am 6 foot 1 and a half inches tall... I have no idea how many centimeters of snow it takes to bury me! I see snow fall in CMs, rain fall in MMs temperature in celsius ... but my height and weight in imperial. (Never mind speed... and distances...)

I have been looking for local sources of sheet aluminum and I have a couple of questions about what kind to get. I never knew that there were so many types.

Should I get "Heat Treatable" or "Non Heat Treatable"? I understand that one could be treated with heat to make it harder (I guess...), is that something I need? I have not requested a quote yet, so I do not know which one is more expensive.

I will guess "Non Heat Treatable" is the way to go.

Aluminum Plate? Is that just plated steel? If so.. I doubt that would be for me...


Grades...
1100 H14
3003 H14
5052 H32

Can I just go with the cheapest?

Thanks again!

 

[bassboy1]

Thank again for all this golden info! Metric system is great if you were born directly into it. I was in school when we turned over here in Canada... I am 6 foot 1 and a half inches tall... I have no idea how many centimeters of snow it takes to bury me! I see snow fall in CMs, rain fall in MMs temperature in celsius ... but my height and weight in imperial. (Never mind speed... and distances...)

I have been looking for local sources of sheet aluminum and I have a couple of questions about what kind to get. I never knew that there were so many types.

Should I get "Heat Treatable" or "Non Heat Treatable"? I understand that one could be treated with heat to make it harder (I guess...), is that something I need? I have not requested a quote yet, so I do not know which one is more expensive.

I will guess "Non Heat Treatable" is the way to go.

Aluminum Plate? Is that just plated steel? If so.. I doubt that would be for me...


Grades...
1100 H14
3003 H14
5052 H32

Can I just go with the cheapest?

Thanks again!

More grades than that. 2011, 2014, 2017, 5005, 5083, 5086, 6061, 6063. Heat treatings are.... Well, I don't want to go there.
Read here.
https://www.aircraftspruce.com/catalog/mepages/aluminfo.php

I would stay away from the 3000 series and below. 5083 is the absolute best alloy for boat building, and it is what I am looking for in my 20 footer. 5052 is a fairly good marine alloy, and most "tinnie" manufactures (Lowe, Lund, Alumacraft, Tracker, etc) use it. In the 5083 builds, most guys use 6061 extrusions. On my rig, I used 6061 T6. It is easily weldable, but not easily bendable. For most deck uses, anything in the 5000 or 6000 series is just fine. The other alloys (5083 etc) really show advantage in an all time saltwater rig. If I am not mistaken, 6061 is the cheapest. If you are planning on bending, don't use anything above T4. The T6 requires extra efforts to make it capable of bending.