Corrosion too far gone?

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Agauntt38
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Corrosion too far gone?

#1

Post by Agauntt38 »

Thanks ahead of time for all your guys time-
I am in the midsts of doing some restoration to a 14ft aluminum (riveted) Starcraft semi-v. I finally decided to replace the transom and as I dig deeper into this project I am trying to determine the best means or repair because the corrosion is a lot worse then expected. Behind the transom board the aluminum is extremely corroded across the entire back of the boat. My first thought was to use the low temp brazing rods, but the pitting is pretty significant, I wonder if the aluminum is too far gone.
Just unsure about what would be the next best move on repairing/replacing this aluminum.
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gandrfab
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Re: Corrosion too far gone?

#2

Post by gandrfab »

Are you replacing it wood with wood?
Agauntt38
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Re: Corrosion too far gone?

#3

Post by Agauntt38 »

Yes yes I already made the wood transom. The problem area is that aluminum it will be sitting on
Agauntt38
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Re: Corrosion too far gone?

#4

Post by Agauntt38 »

gandrfab wrote: Thu Apr 30, 2020 5:51 am Are you replacing it wood with wood?
Yes. I did a little research and spent some money on good wood and epoxy so it won’t create this issue again
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gandrfab
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Re: Corrosion too far gone?

#5

Post by gandrfab »

One of the guys may recommended a good cleaning product for the old pitted aluminum.

Bolt it and clamp it together the same as laminating a glass hull. Might add an 1/8" transom plate between the old sheet metal and outboard.

If it was a welded hull I would look into framing with extruded aluminum and welding it in place.
Agauntt38
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Re: Corrosion too far gone?

#6

Post by Agauntt38 »

gandrfab wrote: Thu Apr 30, 2020 7:58 am One of the guys may recommended a good cleaning product for the old pitted aluminum.

Bolt it and clamp it together the same as laminating a glass hull. Might add an 1/8" transom plate between the old sheet metal and outboard.

If it was a welded hull I would look into framing with extruded aluminum and welding it in place.
Copy that. I figured those would be my two best options. Would you recommend one method over the other?
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gandrfab
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Re: Corrosion too far gone?

#7

Post by gandrfab »

I'm a welder. If I could weld it I would.

Your base material may not lend itself to welding seeing that it is riveted together.
Agauntt38
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Re: Corrosion too far gone?

#8

Post by Agauntt38 »

gandrfab wrote: Thu Apr 30, 2020 9:48 am I'm a welder. If I could weld it I would.

Your base material may not lend itself to welding seeing that it is riveted together.
Thanks for your help man. I have a someone who will weld it for me but he doesn’t specialize in boats. He wanted to make sure it was the right move before I had him do it.
I am thinking I’ll have the top half cut out flush with the shelf that the transom board sits on.
Tfitz
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Re: Corrosion too far gone?

#9

Post by Tfitz »

Why not drill the rivits out and replace the aluminum and rerivit it? I rebuilt a starcraft than had cracked at the chines on the hull. Had to remove about all the cross ribs in the boat. Over a 1000 rivits. Factory guidance was very helpful. Bought the rivits from them too. That aluminum is so thin it will be very weak after welding and if you get the corners hot you will destroy the mastic seal sandwiched under the molding. I used an aircraft pneumatic riviting gun to do the job. Those rivited boats are pretty disposable, someday get a all welded boat.
Agauntt38
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Re: Corrosion too far gone?

#10

Post by Agauntt38 »

Tfitz wrote: Sat May 02, 2020 1:55 am Why not drill the rivits out and replace the aluminum and rerivit it? I rebuilt a starcraft than had cracked at the chines on the hull. Had to remove about all the cross ribs in the boat. Over a 1000 rivits. Factory guidance was very helpful. Bought the rivits from them too. That aluminum is so thin it will be very weak after welding and if you get the corners hot you will destroy the mastic seal sandwiched under the molding. I used an aircraft pneumatic riviting gun to do the job. Those rivited boats are pretty disposable, someday get a all welded boat.
That seam has a lot of rivets ! I’ve never dealt with rivets but I am sure it’s nothing YouTube couldn’t learn me. I’ll have to look into that a little more. But you’re absolutely right, next boat will have zero rivets! Thanks for the input!
kmorin
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Re: Corrosion too far gone?

#11

Post by kmorin »

Aqauntt38,
before committing to any one course of action I'd suggest you contact https://www.fishonfabrications.com/ in GA. The owner there does this type of work pretty regularly and would give more of a 'been there done that' reflection on the various methods and results he's seen.

I've done this project on a little larger riveted boat in the past and all the remarks about caution and investigation before you go ahead - seem very well considered in my experience. That's from someone with more than a few skiff builds (in &) out of his shop in the last 50 years.

Scantlings proportions, alloys' composition, welding methods vs riveting results, material (alloy properties) work hardening, and several other items mentioned make this type of repair one which could use some research and reference by those who do this work regularly.

cheers,
Kevin Morin
Kenai, AK
kmorin
Agauntt38
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Re: Corrosion too far gone?

#12

Post by Agauntt38 »

kmorin wrote: Sat May 02, 2020 1:49 pm Aqauntt38,
before committing to any one course of action I'd suggest you contact https://www.fishonfabrications.com/ in GA. The owner there does this type of work pretty regularly and would give more of a 'been there done that' reflection on the various methods and results he's seen.

I've done this project on a little larger riveted boat in the past and all the remarks about caution and investigation before you go ahead - seem very well considered in my experience. That's from someone with more than a few skiff builds (in &) out of his shop in the last 50 years.

Scantlings proportions, alloys' composition, welding methods vs riveting results, material (alloy properties) work hardening, and several other items mentioned make this type of repair one which could use some research and reference by those who do this work regularly.

cheers,
Kevin Morin
Kenai, AK

Thanks for the input. I reached out to the guy you mentioned so hopefully he gets back to me! Who would’ve knew such a repair was so intricate...
I see you’re from the Kenai, almost time for the salmon run! I’m convinced Alaska has the best fishing
Tfitz
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Re: Corrosion too far gone?

#13

Post by Tfitz »

If you want direction from none other than professionals doing exactly what your are attempting to do why not call the Starcraft factory people? I did, talked to the forman in charge of all warranty and maintenance repair work for StarCraft. He had been doing that work everyday for 30 years. Told me exactly what caused my problem and how to fix it. Sold me all the materials to fix it as well. He was very knowledgeable and a pleasure to work with. But he told me "you do the repair my way or hit the highway" he wanted NOTHING to do with the repair unless you followed his guidance.
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gandrfab
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Re: Corrosion too far gone?

#14

Post by gandrfab »

Bet he has many roads and streets named for him. ONE WAY

(Closed minds are always the best to work for and or deal with. They won't even understand why, it's great.) <--- is all sarcasm.
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Re: Corrosion too far gone?

#15

Post by Tfitz »

I think the factory formans attitude came from the fact that he knows the boats and how to repair them from every angle and has seen and done it all and had no time for my ideas taking short cuts on his methods. His method was very labor intensive but after i started the repair i could see it was the best way
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gandrfab
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Re: Corrosion too far gone?

#16

Post by gandrfab »

I understand.
One way can be a great way. And in his postilion it is the only way.

The whole old dog and new tricks comes in to play, "always" never applies to a closed mind. It is what it is.
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