Landau 1470 Rebuild: Aluminum Frame Casting Deck & Floor

[DocBrown]

Hi folks. This is my first post but I've been lurking and using the forum as a reference for quite a while. I'm in the process of rebuilding my Landau 1470 Jon boat. My dad originally did a "bass boat conversion" on the boat in the 80's and I redid the boat in early 2000's w my brothers. It spent a lot of time out in the weather and was in need of attention if I'm going to keep fishing out of it with my kids.

The plan is extend the front deck and redo all the framework in aluminum to reduce weight vs previous builds which used wood framework. The most recent build w/ my brothers had two large pedestal seat bases, one on the main lower floor, another on a step up toward the front, and the original short front deck. I'm installing recessed 3/4 pin seat bases, 2 in main floor and one on the new deck. I'm also moving the battery to the front under the deck along with adding a lot of under deck storage with flush hatches.

I'll add more posts with details and progress pics up to this point, but for now check out my YouTube channel to see my intro video.

https://www.youtube.com/watch?v=fJ73jrd75N4

I'll be posting more update videos to cover project progress as I go.

 

[DocBrown]

Here's a recent pic of the boat with my fishing buddy showing off a baitfish he found at the ramp.

Details of the boat: trolling motor is a Minn Kota 40AT, outboard is '87 25hp evinrude w 35hp intake and carb. The new front deck will go to about middle of where front seat post was previously.


Patch panel over bad spot in the transom.


Initial tear down.


My brothers and I used a lot of wood during that early 2000's rebuild and it was all trashed.


This whole project really started with rebuilding the transom and supports

 

[DocBrown]

I decided to build my own recessed pedal tray after looking at pricing online. I cut each panel out and welded it all up.





I'll be adding a flange around it for easy install and removal if needed. This is about where it will go on the new deck.



The lid on the livewell needed some attention around the hinge.

 

[DocBrown]

Here's the hull after vacuuming and powerwashing it. It was crazy the years of built up dirt and gunk that came out of the ribs.



Before I did anything I worked up a sketch to scale with my layout and then also tried it out by mocking it up in the driveway. I also used the sketch to estimate material needed and purchased from a local supply in 24' pieces. Much more cost effective than Home Depot or lowes (close to 50% less per foot)





The next thing I did was flip it over and repair any suspected leak areas. This is another lesson area regarding galvanic corrosion and why to not use pressure treated wood and mild steel fasteners. I was able to push a pick through some of the corroded spots. Then I'd drill it out larger to get to clean base metal, weld it up, grind & smooth it out.





This one was under a rib and no matter how much I cleaned it would just keep blowing out from corruptions contamination. So it got a patch.

 

[onthewater102]

Bookmarking this for others benefit to share as an example of why you NEVER use pressure treated wood.

That said you're doing beautiful work - given your aluminum welding abilities I hope you're doing this over with all aluminum framing so your fishing buddy doesn't have to rebuild this boat when it makes its way to his hands.

 

[DocBrown]

Bookmarking this for others benefit to share as an example of why you NEVER use pressure treated wood.

That said you're doing beautiful work - given your aluminum welding abilities I hope you're doing this over with all aluminum framing so your fishing buddy doesn't have to rebuild this boat when it makes its way to his hands.

Yeah unfortunately some lessons are learned the hard way...plus the internet was in its early days when we did the rebuild and there just weren't a lot of good references.

You're right on track, I am building all the framework out of aluminum for that exact reason. I'm also reducing weight while increasing hull ridigity so I'm hoping it will pick up some speed and ride a little smoother. I've weighed everything that came out and everything that's going in and I'm down 30lbs from before.

 

[DocBrown]

After I finished patching the hull I began setting up the framework for the front deck. I'm using thick wall (11 gauge) 1" aluminum square for the majority of the top of framework and 16 gauge for the vertical support pieces. There are three main spans that will be welded to the sides of the boat acting as crossmembers for the remaining deck surface.





I'm using stainless 1/4-20 threaded rivnut inserts for the seat mounts since I wouldn't have access underneath for a through-bolt and I did not want to use sheet metal screws in these locations. I originally purchased aluminum inserts and tried one out with the mount on a scrap piece with good results. But after thinking it over I chose stainless inserts due to the softer properties of aluminum vs stainless steel and this being a more critical fastener joint that I didn't want the bolt tension to relax due to thread deformation.







I'll also be using these rivnuts up front to mount the trolling motor.

 

[DocBrown]

I originally planned to weld in the rear floor stringers to the ribs in the floor. But after seeing the corrosion and the challenge I had with patching the bad spots in the bottom I decided to take a different route and save myself some headache. I cut and welded 1" angle tabs to each one and then riveted to the floor ribs after installing the foam board.



There will be an additional layer of foam sheet running between the stringers.



I did similar tab work on the middle crossmember which will be riveted to the front floor rib. The second and first cross member supports have the tabs that I will drill through the hull and secure with solid rivets.



Here's a general layout. There is framework for the trolling motor that will get threaded inserts just like the seat mounts.



I finished up the front framework as much as possible without welding it into the boat so I'd have more access to weld it out once it was ready.

 

[Spedly]

Nice work. I like how you raised the floor up off of the ribs.

 

[onthewater102]

Those rivnuts are fantastic. I had originally considered a sort of removable storage setup for the front of my boat where I could pull a portion out and have more floor space for the family - sort of an on demand deck extension. That could be easily done if the deck framing were able to be bolted in...

 

[Zum]

Subscribed...nice work, enjoyed the video as well. There's a couple things I'd like to do to mine but I know the little miller 130 isn't the tool for the job.

Sent from my SM-T350 using Tapatalk

 

[DocBrown]

Thanks for the kind words. I did quite a bit of measuring and planning before I did any actual work. Haha.

The main reason for raising the rear floor was for clearance of the recessed seat posts. With the square tube and 1/2" ply it works out just right.

Check out my update video with details of the deck framing.
https://www.youtube.com/watch?v=dCx2N8e9qo4&sns=em

I've already started cutting and laying out the decking so I'll get some pics and video up in the next week or so.

 

[TDobb]

Very nice work. The welded assemblies look awesome. Super clean framing and installation. Well done so far and can't wait to see the finished product.

 

[DocBrown]

Framework is all done and completely welded in. All of the foam board is cut and installed in the rear floor now. I'm using two pieces of plywood for the rear floor with the strength axis perpendicular to the supports. This allows me to use thin sheet (15/32) and will give great stiffness with minimal weight.



Fitting the main front deck sheet.



I had to crawl under and trace hatch locations.



Deck with hatches cut out and recessed tray dropped in place.



With middle hatches dropped in. Still need to cut the side hatches.



Next is trolling motor mount, trimming and fitting the hatches, and getting all the holes drilled in the deck.

 

[fool4fish1226]

Very nice work

 

[Ictalurus]

Great job doc!!!

My previous rig was the landau 1470 and it was a great boat. Like yours, both bench seats were removed in my boat. I didn't secure the sides well enough the first go round so I had some flex when I'd put my 20 hp on there. The second rebuild was tied together much better and I never noticed any flex. Link is below if you want to see another 1470.

Good luck on your build.

 

[DocBrown]

Great job doc!!!

My previous rig was the landau 1470 and it was a great boat. Like yours, both bench seats were removed in my boat. I didn't secure the sides well enough the first go round so I had some flex when I'd put my 20 hp on there. The second rebuild was tied together much better and I never noticed any flex. Link is below if you want to see another 1470.

Good luck on your build.

Thanks man! Glad you chimed in here, your builds was one of a few landau posts I found through search way back even before I was a member (I think I have it bookmarked...haha). My layout was very similar to yours with a stepped front deck. I found that it was a pain to fish because when flipping I was always having to get over the sides of the boat. I could stand on the front deck, but then I couldn't run the trolling motor because the pedal was down on the lower deck...so that's what pushed me to extend the front deck.

Considering how rotten all the wood was in this thing I will have much less flex than before, especially with the extended deck welded into the hull.

 

[DocBrown]

Both rear floor sheets have been cut to fit with holes for seat bases. I'm marking all the areas I will predrill oversize so they won't lift when I shoot in ss self tapping screws.



All the front deck and hatches are also cut out and trimmed to fit carpet and hinges. Also cut holes for 6.5" speakers. I've got a kenwood marine Bluetooth amp to run those guys when tunes are needed.





I have stainless piano hinge that I will mark and predrill holes for the hatches next.

 

[onthewater102]

Such beautiful craftsmanship - can't wait to see the end result.

 

[Johnny]

I agree with OTW - very nice craftsmanship !!!

are you going to treat the plywood in any way ?
or just lay the carpet on raw wood.