1977 14' MonArk Transom Replacement

SC Surveyor

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Greetings to all. First time posting but have been learning from y'all for months.
I'm restoring a 14' aluminium jon boat thats been sitting for 10 years, starting with the transom. Pics will follow (with questions I'm sure) very soon. I would greatly appreciate any input. My first question is about reactivity of different metals to aluminium. Can I use galvanized steel bolts to remount grab handles and other hardware to the hull. I had to cut the old bolts off to remove the transom board to start.
Thanks for any help you can offer!
 

Woodonglass

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Welcome to iBoats!
I recommend two things. 1.) Never use Pressure Treated wood in an Aluminum Boat. 2.) Use Stainless Or aluminum hardware whenever possible. Pics are ALWAYS helpful.
 

Yacht Dr.

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

My first question is about reactivity of different metals to aluminium. Can I use galvanised steel bolts to remount grab handles and other hardware to the hull.

Welcome to Iboats SC..

Aluminum is prone to electrolysis in salt water applications. Try to find fasteners/rivets that are alum.

I would never use galveys on a boat .. no matter fresh or salt.. just me though.

YD.
 

ezmobee

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Stainless is used from the factory on our aluminum boats and will work fine.
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Thanks for the input. Rest assured - NO treated for this transom. I'm using 1/2" marine grade laminated in 3 pieces to get a 1 1/2" thickness. That should be enough for a 15 hp Evinrude.
Pics will follow soon.
Thanks again for the advice.
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Tried to post some pics. of the transom this week but the wife had our camera jacked up to max fine, so all my pre-demo shots are about 2.5 MB each. Swapped out the galvanized bolts for stainless and put new bearings in the hubs last weekend. Plan to rewire the trailer and replace lights and bumper boards this weekend so I can trailer the hull to a good welder. The top lip of the transom was cracked in 5 places and already had 2 welds on it so, right or wrong, I cut the whole piece off and an replacing with 1/4"x1 1/2"x 1 1/2: alum. angle and having it welded to the top of the stern between the corner braces. It also had cracks in the gunwale right in front of the corner braces, so those will get welded too. The pics of my structural engineering will follow soon!
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

View attachment 97932View attachment 97930View attachment 97931


Here are a few shots of the transome board on the boat and removed. Had some pitting behind that wood. Notice the cracks and welds that were hidding under that alum. bracket the motor was resting on. Got the trailer finished this weekend. Hope to get to the welders tomorrow morning.
 

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SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Should be getting the motor out of the shop today and picking up the boat from the welder this evening. Hopefully I can get it put together this weekend. It would be great to get a test run in on Fathers Day. I need to adjust the location of the motor on the stern before I go to far with painting. Last time I ran the boat with the new prop ,the tiller felt like it was pulling out of my hand to port and the boat wanting to steer to starboard. The mechanic advised me to move the motor to starboard in SMALL adjustments until the boat ran straight with no pressure to steer either way. We'll see how this plays out.
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

IMG_3169.jpg IMG_3170.jpgIMG_3168.jpgIMG_3167.jpgIMG_3171.jpg


Happy Fathers Day to all. Here are a few pcs of the boat after the welding was done on the stern and with the new transom board bolted in place (temporarily). I had to double check to make sure I was buying stainless fasteners and not PLATINUM! Still have to paint the stern and transom board before final install. Wanted to set the motor and adjust it's location before the last bolt holes are drilled and sealed. That small piece of alum angle on the seat was all the waste left over from a 10' stick.
 

ezmobee

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Well that sure ain't goin' nowhere! Nice.
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Well that sure ain't goin' nowhere! Nice.

Thanks. I thought the two pieces down the back of the stern might be overkill, but what else would I do with that angle besides forget which corner of the garage I hid it in. The motor should be out of the shop by Tuesday night so I may be playing hookie from work on Wednesday just to try it out. Gonna be 102 outside but what better way to cool down than a nice boat ride!!!
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Got to work yesterday morning with chest bowed out over how much I had done on the boat this weekend. Spent $120 on stainless hardware to fasten the transom board and side braces, fit it all together, drilled the new holes and tightened it down to check the fit. Man it looked pretty good. A co-worker with a ton of automotive experience asked if I used anti-sieze on the threads before I torqed it all down and when I replied "NO, WHY", he laughed. Now I KNOW why. After stewing over his explanation all day I went home and tried to take the board back off. LET THIS BE A WARNING!!! NEVER tighten down stainless without using the anti-sieze on the threads of the bolt first. Of the 14 bolts I tightened down, 12 are junk! I sheared of 8 and the other 4 nuts wouldn't thread back on the bolts. I offered my 6 year old son 5 bucks to kick me as hard as he could in the rump, but he wouldn't do it. Said that was mom's job and he'd go get her. So, today I go back to Lowe's for more hardware. Maybe I can talk them into an exchange. Live and learn people, live and learn.
 

Yacht Dr.

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

After stewing over his explanation all day I went home and tried to take the board back off. LET THIS BE A WARNING!!! NEVER tighten down stainless without using the anti-sieze on the threads of the bolt first. Of the 14 bolts I tightened down, 12 are junk! I sheared of 8 and the other 4 nuts wouldn't thread back on the bolts.

1. What explanation did he give you ?
2. Shearing off Bolts you say ? .. after just a few days ? BOLTS and NUTS "SHEARING" only after a few days ??
3. If this happened .. you Over tightened the Crap outa them nuts m8. ..

I have Never used Anti-sieze on Any bolt on a boat ( Im no mechanic and they use it all the time for nuts and bolts..but they dont use it close to mounting bolts ).

Hmm.. Dont understand why Bolts would shear off like that after a few days..much less weeks..or years..

YD.
 

SC Surveyor

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

Here's how it was explained to me. Because the stainless steel is softer, when the nut starts to tighten on the bolt, it creates "galls" on the nut and threads due to the heat generated by friction. When it cools and you try to back them off it's like trying to push two files across each other against the grooves. I am 6'2"/230 but didn't think I put that much on those bolts, but I needed the board snug to straighten out the bow in the stern caused by the old bad transom. Granted, my enthusiasm for getting to this point in the resto. my have gotten the better of me, but I knew I still needed to take that board off to seal and paint the inside of the stern. Lowe's was good to me though and gave a full refund. Had to go to two stores to get all the replacement parts, and niether of the "hardware associates" had heard of this issue. Once I get the transon prepared, I won't have to take the board off unless a repair is needed. Painting on the stern and board begins tonight if the weather holds, and hope to get it in the water for a test run Saturday morning to align the motor.
 

Yacht Dr.

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Re: 14' MonArk Transom Replacement

Re: 14' MonArk Transom Replacement

After further review..I can only think of why you have 5/16 or 3/8 bolts shearing.

1. Bad batch of bolts..
2. Over tighten nuts..
3. Turned the Heads instead of the Nuts.
4. Cross threading.

Nothing else comes to mind...sorry..

YD.
 
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