Replacing the transom on a 14ft Aluminum

[Blake0912]

Hi guys I had another thread about this same boat but my question/goal was kinda all jumbled together so I started a specific one for my question. I am going to replace the transom on my 1977 14ft aluminum Mirro Craft because the PO did not do a great job and PT wood was used. The transom was installed in 2007 and he confirmed with me that it was infact PT wood that was used I did research on the internet and read many threads here on the subject and there is mixed feelings about using PT wood with aluminum. In my opinion my boat would have already been affected by the chemicals since it has already been 4 years since its been replaced, since i did not see any signs on the aluminum corroding. Now my question is, what type of wood do I need to use for this job? I think two 3/4in ply wood sheets would be to thick because the board on it now is only 1/2 thick and 9in tall at the highest point. Should I just go buy one of thouse 1/2x10 or so support beams and use that? And also Ive read that It needs to be coated in epoxy resin for the best results..can I buy this at lowes?( Sorry if i sound dumb ive never used the stuff before ). And one last note, I noticed that on 3 out of the 8 main bolts supporting the transom the aluminum on the brace and starting to split from stress I would imagine. Should I just add 2 more bolts of so above the point of where it is splitting to add some extra support? Ill include some pics of the splits I am talking about. Thank You

 

[jasoutside]

Re: Replacing the transom on a 14ft Aluminum

Is it really only 1/2" thick? Can you go thicker or does that transom cap only take a 1/2" piece?

As for what you replace it with...

Marine Grade, Arauco Ply, MDO or Exterior Grade are all fine. Just seal it up with epoxy, or paint at least.

Have ya got just a little wider photo of your whole transom? Maybe you can just drill new holes for that alum support structure? Maybe.

Cheers

 

[Blake0912]

Re: Replacing the transom on a 14ft Aluminum

Ah i ment 1 1/2 inch typeo lol. I was thinking about just using two 3/4 peices of ply sandwitched together to get the 1 1/2 inch width and also there is no outside transom..should there be in this type of boat? And I could drill a hole in the middle of the supports and add 4 new bolts total. Another question would I have to use some type of glue to hold the two peices of ply together or would the bolts be enough?

 

[Blake0912]

Re: Replacing the transom on a 14ft Aluminum

Here are some more pics of the transom

 

[jasoutside]

Re: Replacing the transom on a 14ft Aluminum

Ah i ment 1 1/2 inch typeo lol. I was thinking about just using two 3/4 peices of ply sandwitched together to get the 1 1/2 inch width and also there is no outside transom..should there be in this type of boat? And I could drill a hole in the middle of the supports and add 4 new bolts total. Another question would I have to use some type of glue to hold the two peices of ply together or would the bolts be enough?

Well that's better. Yah, two 3/4" pieces laminated together with Gorrilla Glue, Epoxy, Tightbond III, PL Premimum - all good options. Just bolting them together is no good as water will find it's way in and start the rot on it's way.

Nope, transom on the outside is unnecessary.

Have fun, should be a great project!

 

[Bob_VT]

Re: Replacing the transom on a 14ft Aluminum

You know......... you might want to make it a bit taller. Your motor is mounted too low and at the proper height you will get better performance

 

[Blake0912]

Re: Replacing the transom on a 14ft Aluminum

Thanks for your responses now I have a good place to start. As far as the motor being to low I think its just the way the pic in angled the captivation plate is pretty level with the bottom of the boat and it runs/stays on plain fine and its been like that for so long I dont want to mess with it.

 

[ezmobee]

Re: Replacing the transom on a 14ft Aluminum

Yeah, you've got a long shaft motor on a short shaft transom there. That will have a significant negative impact on performance.

 

[Blake0912]

Re: Replacing the transom on a 14ft Aluminum

Just out of curiosity what would the length of a "long shaft" be vs a short shaft? I swear this is a short shaft motor

 

[Blake0912]

Re: Replacing the transom on a 14ft Aluminum

The mid section measures 17in from the bottom of the powerhead to the top of the LU and the captivation plate is level to the bottom of the boat. Sounds right to me...

 

[jasoutside]

Re: Replacing the transom on a 14ft Aluminum

15" - 17" = Short Shaft

18" - 21" = Long Shaft

Your cavitation plate looks like it's roughly 5" lower than the hull in that photo there.

 

[Blake0912]

Re: Replacing the transom on a 14ft Aluminum

Its actually even with it guess the angle on the photo is just weird. Im thinking about getting a newer style motor im not a big fan of the LU on this one and it is very corroded on the inside i found out today after trying to replace the water pump I still have yet to get the LU to break free but will prob run it with this for the rest of the season then upgrade. I picked up supplies for my transom and will start the work tomorrow. Ill post some pics of the work. On a side note I took it fishing yesterday and it preformed awesome and got lucky with some fish im very happy with the hull just a little frusterated with the motor.

 

[hondarider188]

Re: Replacing the transom on a 14ft Aluminum

looks like in the picture that the transome saver is on and that it is propped up, hence it looks like it is looks like it is lower than the hull. then the angle of the picture cant help either. but thats my guess from what i could see.