Replacing transom wood- without disassembling aluminum

[db4570]

I have an old 1963 Aluma Craft 14 footer that has seen better days. The transom wood is rotted out, inside and outside. I want to replace it, but the inside piece is covered by the aluminum frame of the transom. It looks like I can remove the old wood by chipping it out, but I can't figure out how to get the new plywood back in there without disassembling the entire stern of the boat.

I am actually thinking about essentially laying up my own plywood, one ply at a time, which I can bend enough to slide into the slot there. I figure coat the plys with enough good glue, clamp each one down while it dries, and how hard could it be?

Is this an insane idea? Is there a better way?

Thanks for any suggestions.

David

 

[DaleH]

If it were me ... I'd at least get that transom 'top cap trim' piece out of the way. Even if you can't fully remove the 2 corner end caps off completely, you should be able to 'lift' carefully the end on the top cap. If/as needed, anneal the corner brace before bending by coating the area to bend with a Sharpie marker and apply heat from a propane or MAPP torch, and when the marker sizzles - bend slowly. That alloy will air harden when cooled.

This would be easier ... you could even just cut the trim cap in half and sneak each piece out by lifting the 1st one over the other and moving it toward the middle of the boat, as long as you remove that bole from the corner caps. That too should give you enough room to work in there.

Buy the sample epoxy kit for $24 or so from Raka epoxy and get it done right ... www.raka.com

 

[mbullen]

Standard procedure for the Aqueduct Transom is to remove the two small brackets in the splash well. Simple drill the rivets and lift out. With the brackets out of the way, the wood is easily pulled down and out. Reassembly can be done with threaded bolts if it's easier on you. Be aware of the space for the splashwell drainage holes when cutting a new piece.

The traditional route of up and out through the cap and corners is going to run into welded obstacles.

 

[Colorado1135]

Bingo that's exactly what I would do. I have a rivet gun and correct rivets so that's what I would use to keep it as close to original as possible but if I didn't I would just use bolts like mentioned. Easy replacement you can do in a light afternoon

 

[DaleH]

Looks like a more elegant approach!

 

[db4570]

Ah! That looks like a great method, Mbullen.

What would be the proper type of rivets? All I have are pop rivets. If I decided to go with bolts, will stainless cause any galvanization woes? (This poor boat is really far from original. You should see the giant welded patch on its side).

(Thanks for your detailed reply, DaleH, but that looks like a pretty major project.)

Thanks,

David

 

[mbullen]

Rivets would be aluminum in the length and diameter needed. (*solid rivets - usually a brazier, modified brazier, or universal head.)
Personally, I have used 316 stainless threaded hardware with some 3M 4200 sealant here. It's well above the waterline.

Stainless is indeed a dissimilar metal than aluminum, but is perfectly acceptable in the galvanic overlap chart. The receiving aluminum makes a large footprint to disperse the reaction and the wood and the sealant will make a barrier. Some folks go an extra mile with rubber and nylon washers for barriers but I haven't personally gone to those lengths.

 

[DaleH]

Stainless is indeed a dissimilar metal than aluminum, but is perfectly acceptable in the galvanic overlap chart. The receiving aluminum makes a large footprint to disperse the reaction and the wood and the sealant will make a barrier. Some folks go an extra mile with rubber and nylon washers for barriers but I haven't personally gone to those lengths.

Believe me ... it WILL cause problems if the boat is used is saltwater. Anyone with an old green or black Penn or black Garcia Mitchell reel used in the salt can verify it for themselves. Did you ever have the paint coming off near a screw but it also looked like it was bubbling? And maybe you saw white powder' under the paint chipping off? Yup ... galvanic corrosion that was caused by the SS screw used to fasten the sideplate onto the aluminum reel(s).

Heck, on my 1st tin conversion, I just used duct tape underneath the washers on either side of what was fastened to the tin, like that under the head of the bolt or the nylok nut ... and it worked. I just tried to up my game as of late, lol!

 

[mbullen]

Believe me ... it WILL cause problems if the boat is used is saltwater. Anyone with an old green or black Penn or black Garcia Mitchell reel used in the salt can verify it for themselves. Did you ever have the paint coming off near a screw but it also looked like it was bubbling? And maybe you saw white powder' under the paint chipping off? Yup ... galvanic corrosion that was caused by the SS screw used to fasten the sideplate onto the aluminum reel(s).

Heck, on my 1st tin conversion, I just used duct tape underneath the washers on either side of what was fastened to the tin, like that under the head of the bolt or the nylok nut ... and it worked. I just tried to up my game as of late, lol!

Oh yeah! Salt accelerates the whole equation. Marinas with leaky shore power, too.

I guess I'm fortunate to be in the TVA freshwater reservoir system and my boats live on their trailers.

...but now I'm having nightmares about old tinnies berthed in a salt marina with charged water and full of treated lumber. Lol.
Thanks for that visual, DaleH. Yikes.

 

[db4570]

I don't think this boat will ever see salt water. It hasn't in its 60 years, anyway.

Now the question is what type of wood? Rather than fool around with plywood, how about a nice thick white oak board?

 

[mbullen]

I don't think this boat will ever see salt water. It hasn't in its 60 years, anyway.

Now the question is what type of wood? Rather than fool around with plywood, how about a nice thick white oak board?

White Oak, Mahogany, and marine ply are the usual suspects.

The inner board/yoke thickness is dictated by the cavity in which it sets, however the outer board/motor pad is a little thinner - making up the remaining gap in what's available to use in the widest setting of the transom clamps.
Usually folks use ply on the outer because it's stronger in the the thinner dimensions.
For what it's worth, the factory also used a cork sheet under that outer pad, too.

The main thing is to avoid treated materials as all treatment processes use some type of metal, usually copper, and you're then right back to the dissimilar metal problems.

 

[MstrDan]

db4570, I have a 1967 Alumacraft and had the same problem when I first got it. mbullen posted has posted the proper method and great instructions. Unfortunately for me I had to learn the hard way . I could not save my top transom plate, so I made one out of aluminum angle. Take your time and remove the rivets. It will be worth the effort. I got aluminum rivets for mine from Amazon. White oak is the wood originally used by Alumacraft.

 

[db4570]

I'm now looking to possibly sell it and buy another boat. I hate to say this, because I never used to be so vain, but this thing is just embarrassingly ugly. It has just been beaten up (by the previous owner.) I'm seeing a few tin boats in much nicer condition for reasonable prices.

 

[LaqueRatt]

Not that hard to turn ugly into respectable. 5 hours of labor and $70 for materials.

 

[CO_4X4]

Not that hard to turn ugly into respectable. 5 hours of labor and $70 for materials.

How much purple power acid wash did you have to use on that? . Took me 3 gallons to get that level of black off my boat before it looked like normal aluminum again. Great job, that's an outstanding before and after!