19ft prince craft Hudson rebuild

[Jamesburslem]

Hello everyone.

new to the forum and happy to be here.

well here’s my story and how I ended up with this project. In Sumer of 2022 looking over kijiji adds in my local area I came across this 1999 prince craft Hudson. 19’3” long and 84inches wide. I got the fella to send me photos and was dimly interested as he came across as a jerk. The boat looked ok via the photos he sent but with a baby on the way my priority’s were focused on another direction. He was offering the boat and 60hp Yamaha and trailer for 4g. Wasn’t horrible but again don’t like arrogant jerks so I left it alone. Last week in between changing diapers and getting barfed on a text message showed up on my phone. “ would you still be interested in the boat “ being that jt was only 2 hrs away and I was heading down there anyways I went to see it. It’s rough but for what he offered it to me for I figured I could make something out of it.
So for 2500$ I got a fully custom loosely riveted hull that leaks like a siv a good 60hp Yamaha and a trailer that needs some new rollers.

We are in the middle of winter here in barriere bc so it’s presently defrosting in the shop. I was doing some measuring today and found two cracked ribs. I’m not concerned about them as I am a certified welder with 12 years experience.

I am planning on stripping out the bench seats and making the floor flat adding in two seats for me and the wife and two jump boxes for the kids. Putting the fuel tank below the floor and checker plating the floor so it’s easy to wash out after a day fishing.

I have a huge engineering question. I am planning on removing the bench seats as they have been chopped and hacked at by previous owners and I hate jumping over seats to set the hook off the down riggers.

I am going to cut tapered braces to run from side to side to brace the hull so it stops flexing and so I can put a flat floor into it. What thickness of material should I use. I was thinking 1/8” 5052 aluminum bar 8” wide.
How much material could be removed out of the centre of the braces to help keep the boat a reasonable weight as I’m not repowering. Is there any point in removing material or just leave it a solid brace ?

Any advice is always helpful so if anyone had suggestions on how to go about building a good family fishing machine I’m all ears.

James

 

[Barry]

Hello everyone.

new to the forum and happy to be here.


So for 2500$ I got a fully custom loosely riveted hull that leaks like a siv.
It is hard to see from the pictures. Many if not most riveted thin plate aluminum boats had a mastic put between the overlapped joints. So you cannot just weld over the rivets or joint.

We are in the middle of winter here in barriere bc so it’s presently defrosting in the shop. I was doing some measuring today and found two cracked ribs. If they are cracked through, ie a butt weld without an external or internal
"fishplate" welded in the correct position will often mitigate a crack at the same spot.

I am planning on stripping out the bench seats and making the floor flat adding in two seats for me and the wife and two jump boxes for the kids. Putting the fuel tank below the floor and checker plating the floor so it’s easy to wash out after a day fishing. The seats will hold the foam that is required to meet Transport Canada requirements for level floatation if submerged. Not that anyone would check. If you put checker plating on the floor, if you get fish gunk under it, the boat will
produce an odor. And if you weld the heavier 1/8 inch plate to the thin wall side, you could create a stress concentrations at this joint and I would expect cracking over time. In order to place a fuel tank under the floor, the floor will need
strong stringers to hold the weight and dynamic loading. Lots of regs and guidelines for gas tanks, in enclosed spaces, mounting, venting, access to fittings etc. Probably best to create a rear seat that you can put in portable plastic tanks. Or modify the open transom as below to create a spot on both sides under the current full beam engine well

You will note the short gunwale toward the front that the previous owner added. As well the 45 degree prox gunwale stiffeners that come off the current seats. If you remove these stiffeners, you should continue the 4 inch by 1 inch prox
gunwale flats to the transom of the boat to strengthen the sides.

The seats, because they went reasonably far up the sides also provided support to the vertical midpoint of the side panels. Removing them will permit more flexing, and possibly more cracking. You may have to run a
3 inch by 1 inch angle tray from the bow to the transom to stiffen this as well

I have a huge engineering question. I am planning on removing the bench seats as they have been chopped and hacked at by previous owners and I hate jumping over seats to set the hook off the down riggers.

I am going to cut tapered braces to run from side to side to brace the hull so it stops flexing How are you intending to attach the frames the side of the hull? and so I can put a flat floor into it. What thickness of material should I use. I was thinking 1/8” 5052 aluminum bar 8” wide.
How much material could be removed out of the centre of the braces to help keep the boat a reasonable weight as I’m not repowering. Is there any point in removing material or just leave it a solid brace ?

Any advice is always helpful so if anyone had suggestions on how to go about building a good family fishing machine I’m all ears.

Some better pictures of the cracked stringers and existing floor stringers would help
I do not really care for the full length transom well. It is quite open widthwise to the height from the top of the transom to the level that the motor sits on. I would fill this into restrict water ingress with a fast stop. Say the new open width is 2 feet. So from the gunwale to this new opening, run a sheet up to the front of the open well, Ie isolating the engine well. Now you can create a new space for a couple of portable
gas tanks on each side of the new opening You are not using this space right now except for the battery which could go under the well in front of the motor
James

 

[Jamesburslem]

Thanks for the reply Barry.

I wasn’t planning on welding over the rivets. I have ordered new bucking rivets from fastenal. 3/16x3/8 and 1/4x1/2. I am going to pressure test all the rivets with a modified blow gun and soap and water. Basically a blow gun with some 1/2 hydraulic hose hose claimed arround it so I can pressurize each rivet to 20 psi. Should I pressurize them to a higher psi ? Drill out and replace the ones that are damaged and re-buck the ones that can be tightened.

that’s a valid point and yes a fish plate over top and then welded in place is what I will do.

so the plan for the floor was to build the aforementioned brackets 70”wide with a 2” flat bar welded onto the top. So that I can rivet down the dimond plate. The floor will need to be able to be removed so maintenance can be done ie rebuckin rivets.
I am not sure but I’m concerned about welds cracking as well. I see that princecraft riveted the bench seats in place so I may consider riveting the cross braces in place as well as the ribs are thin / mastic Under ribs
And the heat from the spool gun welds will cause distortion and burn up the mastic. . I was going to put a brace on every second rib to help stiffen up the hull. When it comes to the tank. I have purchased a used stainless 36x18.5x7 inch tank and was planning on removing a 19x7.5 rectangle out of the middle 3 cross braces and then boxing the gas tank channel in with 1/8 material to gain back the strength I would be loosing by removing the middle material from the centre three brackets.

I would like your opinion on this. Should cut two slots on each cross brace and run the 1/8 plate 8” wide from bow to stern and weld them at each cross brace to create almost a i beam floor structure. In my opinion the rivets have failed because the previous owners removed bracing causing the hull to flex and loosened the rivets. The braces from the top of the gunnels have had the hardware removed so they are presently not doing anything. The centre of all the bench seats have been chopped out and openings created for storage. From what I can gather someone who did not understand structural integrity hacked and chopped this boat and removed all structural integrity from it. It started flexing and rivets started leaking then they gave up on it.

as for foam I am going to put closed cell blue or pink sheets below the floor to add flotation. I was concidering using pour foam but due to leaking rivets i want access to the rivets so I can change them out or re buck them. I was going to put foam from bow to stern in between all the new braces.

that’s a great idea Barry. I will include the tray running down each side and drill and rivet threw the hull so that I can again stiffen up the hull. I could then possibly extend a few of the floor cross braces up the side of the hull and tie them into the tray? Or possibly cut a custom floor brace that would span the width of the floor and then up the side of the boat that I could tie into the gunnels as well as the tray? What do you think of this? If I was going to do full hight braces how many of them would you suggest doing ?

What thickness of material do you suggest building with ?

What type of material should I build with ie 5052 or ???

I like your idea if closing in the splash well to create more space. The previous owners have butchered the back and welded a 1/8 formed plate all the way across and riveted threw the hull with some aluminum and some steel rivets. I will be drilling all these out and putting solid rivits in with a dab of 5200 behind all of the new replacement rivets.

thanks for all your help and suggestions. You’ve given me some great things to incorporate into the build. I have attached a picture of the full hight bull heads I was thinking ?

 

[Barry]

Thanks for the reply Barry.

I wasn’t planning on welding over the rivets. I have ordered new bucking rivets from fastenal. 3/16x3/8 and 1/4x1/2. I am going to pressure test all the rivets with a modified blow gun and soap and water. Basically a blow gun with some 1/2 hydraulic hose hose claimed arround it so I can pressurize each rivet to 20 psi. Should I pressurize them to a higher psi ? Drill out and replace the ones that are damaged and re-buck the ones that can be tightened.
I do not have any solid riveting experience so cannot comment.

that’s a valid point and yes a fish plate over top and then welded in place is what I will do.
I only suspect that a rib has cracked through. So you would butt weld this together. If you add in say a top plate to bridge over the butt weld, you have to ensure that the "fish plate" is not welded crosswise to the stringer ie 90 degrees to the
rib or you could have another crack form. Keep the welds longitudinal.

so the plan for the floor was to build the aforementioned brackets 70”wide with a 2” flat bar welded onto the top. So that I can rivet down the dimond plate. The floor will need to be able to be removed so maintenance can be done ie rebuckin rivets.
I am not sure but I’m concerned about welds cracking as well. I see that princecraft riveted the bench seats in place so I may consider riveting the cross braces in place as well as the ribs are thin / mastic Under ribs
And the heat from the spool gun welds will cause distortion and burn up the mastic. . I was going to put a brace on every second rib to help stiffen up the hull. When it comes to the tank. I have purchased a used stainless 36x18.5x7 inch tank and was planning on removing a 19x7.5 rectangle out of the middle 3 cross braces and then boxing the gas tank channel in with 1/8 material to gain back the strength I would be loosing by removing the middle material from the centre three brackets.

I would like your opinion on this. Should cut two slots on each cross brace and run the 1/8 plate 8” wide 8 inches is quite wide, and you should have a lip on the inner part of the flat. 6 x 1 1/2 would be more than sufficient . If you have stiffened the gunnel, you should not need any of these 45 degree supports. from bow to stern and weld them at each cross brace to create almost a i beam floor structure. I am not sure what you mean In my opinion the rivets have failed because the previous owners removed bracing causing the hull to flex and loosened the rivets. The braces from the top of the gunnels have had the hardware removed so they are presently not doing anything. The centre of all the bench seats have been chopped out and openings created for storage. If only the top of the seat was opened up but not cut completely through, ie the seat could still take compression and tension through the rivets attached to the side panel, there should not be a problem. Also the beam will still be strong. I expect that the floor ribs were attached to the bottom of the seat or were they free floating? From what I can gather someone who did not understand structural integrity hacked and chopped this boat and removed all structural integrity from it. It started flexing and rivets started leaking then they gave up on it.

as for foam I am going to put closed cell blue or pink sheets below the floor to add flotation. I was considering using pour foam but due to leaking rivets i want access to the rivets so I can change them out or re buck them. I was going to put foam from bow to stern in between all the new braces. I recently had an extremely poor experience with an Ultrasport aluminum boat that had DAP pour in foam. The boat had about a year of service on it, center console, which I wanted to put a front deck, windshield, remove the center console to change the seating and convert the transom to accept an outboard jet. During the removal of the center console I noticed that the pour foam had absorbed a lot of water. Digging out pieces, I could squeeze the foam like a sponge and water would literally pour out. Searching the web, using wording like "problems with foam in boats" I ran into a myriad of people who had the same issue with pour in foam, many different manufacturers. While the US coast guard sets level floatation standards/regulations, for smaller craft and specify that the boat should meet regs without modification for 10 years, it seems like there was no recourse for remediation. The manufacturer of the hull, the dealer that I bought the boat from and the foam company pretty much stuck their head in the sand. Water trapped against aluminum in the absence of oxygen can cause serious corrosion over time.

that’s a great idea Barry. I will include the tray running down each side and drill and rivet threw the hull so that I can again stiffen up the hull. I could then possibly extend a few of the floor cross braces up the side of the hull and tie them into the tray? Or possibly cut a custom floor brace that would span the width of the floor and then up the side of the boat that I could tie into the gunnels as well as the tray? What do you think of this? If I was going to do full hight braces how many of them would you suggest doing ?
We ran trays down the inside panel of our aluminum jet boats, They made excellent places to store rods, approximate size 4 inch with a 1 inch flange turned up. You could build it in the shape of a channel and rivet this to the side

What thickness of material do you suggest building with ? I am not sure what thickness that your hull sides or bottom is so would not make a call on that. We used 1/4 bottoms, with 1/4 formed stringers, with 1/8 inch sides. So our deck and
trays were 1/8 inch. Our boats with big blocks, jets at 21 feet probably weighed in around 2500 plus pounds, and depending on gear and fuel maybe 4000. If you can weld .100 with your mig, that SHOULD be fine. I say SHOULD because the construction of joints wrt to other members need to be done correctly. But 1/8th is only 20% heavier. Your seats could easily be made with thinner material. We did not attach the bottom to anywhere on the sides of the boats to ensure that we did not create stress concentrations in the sides which could cause fatigue cracks. Longitudinal stringers, angle, then put cross pieces in that did not touch the floor to permit water movement from the front to the back easily. So the floor was a grid.

One comment on weight. The original owner already has added a lot of weight with the deck. You are considering adding a lot more weight. The plywood with say a Duradeck/vinyl coating will add a lot of weight. A stainless steel fuel tank much more. The portable tanks are easier to deal with and light weight. I am only mentioning this as the weight will climb faster than you think and affect the performance of the boat. Mind you it does give you a reason to up the HP.

What type of material should I build with ie 5052 or ??? 5052H32 would be fine

I like your idea if closing in the splash well to create more space. The previous owners have butchered the back and welded a 1/8 formed plate all the way across and riveted threw the hull with some aluminum and some steel rivets. I will be drilling all these out and putting solid rivits in with a dab of 5200 behind all of the new replacement rivets. It appeared that there is lots of unused space back there. Do not forget that to meet regs for the fuel tank is quite comprehensive

thanks for all your help and suggestions. You’ve given me some great things to incorporate into the build. I have attached a picture of the full hight bull heads I was thinking ?

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[Jamesburslem]

We’ll after a few weeks here is what we are dealing with !!!

I am still amazed at the corrosion caused by using the wrong bolts on a aluminum hull. Drilled out lots of rusty steel screws , remove steel self tapping screws , steel rivets and all the steel hardware that someone before me mounted the motor with.

Loose rivets drilled out and new buck in rivets installed.

I laminated 2 sheets of 3/4 marine plywood together for a new transom.

it’s always good to be back rebuilding!!

has anyone used Sherman Williams tile clad on the hull of a boat to create a water tight seal to protect against corrosion fuel and wear?

Thinking out side the box on that. Epoxy is expensive and you have to paint it anyways and cladding is used on the railway and in marine shipping for mitigation of wear and chemical barrier.

 

[Ike]

as for foam I am going to put closed cell blue or pink sheets below the floor to add flotation. I was concidering using pour foam but due to leaking rivets i want access to the rivets so I can change them out or re buck them. I was going to put foam from bow to stern in between all the new braces.

The foam you propose is fine for flotation but first find out if it is a polystyrene. Most of the insulation foams sold in home improvement stores are polystyrene. The issue here is if you put it under the floor it will be exposed to any fluids that are in the bilge. Water is not a problem, but cleaners, gasoline, oil and fuel additives are. They dissolve polystyrenes. So if you do this you need to bag the foam or enclosed it in such a way it is not exposed to fluids in the bilge.. It needs to be sealed up so that no fluids can contact it. Boat Building Projects | 1972 Sea Ray 190 Rebuild https://newboatbuilders.com/pages/SeaRay190.html This is a link to a project boat where I had to reinstall the foam and used the pink foam. As you can see the foam on the sides are covered with plastic sheeting and sealed in. The pink piece in the middle is high enough off the bilge it never touches water. (unless some catastrophe happens)

On the other hand, polyurethane and polyethylene foams do not have this problem. Most 2 part foams are polyurethane. But PU pour foams do have water absorption issues. So oddly enough bagging or putting them in sealed boxes is a good idea. Typical Polyethylene foams are used in pool noodles and other water toys and do not have either issue. the problem with PE is getting it in sizes and shapes for use as flotation and at a cost that isn't prohibitive.. However, some boat builders have used PE foams but it is rather unusual.

 

[Jamesburslem]

I think that’s a great suggestion. The foam noodles are cheep as well. Up here in Canada building materials are very expensive.

the sheet of marine grade plywood was 200$ Canadian for 3/4” 4x8

What do you think about coating the inside of the hull with the tile clad ?