Loweline 1436 Refurb. Need advice from the experienced.

Hello Tinboaters! I have a 1436 that I would like to get water ready again. This boat was running lakes about four years ago. The old engine threw in the towel and it became a pond boat. Someone decided to shoot the boat so it has one entrance and one exit hole to be plug welded. Pics below. That is the easy part. I could really use guidance on how to repair the transom. As you can see in the pictures below a prior owner added the braces in the back corners. The top lip on the transom has been welded and has torn again. Something needs to be done here but I am not sure what needs to be done so it will support the engine weight.

Is the wood area of the transom strictly to stiffen the area to support the weight of the engine? If so is using a solid aluminum plate an option? I have noticed that the new models have a couple aluminum supports added in the back. Would this be a good idea to add? I will find a picture of what I am referring to on this. My transom is not flat and this concerns me. See the picture below and tell me how bad it is.

I appreciate any advice. If this has more damage than is worth repairing please be honest!

Dark green area is the hole to be plug welded




I tapped the exit hole back in place the best I could without beating it.


Entrance



This shows the braces that were added and the problem area




What I'm starting with




The bracing on new models I was referring to.


This worries me. Can this even be repaired? It was very hard to get the camera to capture the gap in the dark. It's pretty large......

With the welding the PO did to re-enforce the transom I'm guessing the transom wood is too weak to hold up any longer. Instead of cutting all the welds I would remove the Z bracket at the bottom of the transom wood to remove the old wood. You may also have to remove the knee brace.
The flatness of the transom might be because of the condition of the transom wood. I wouldn't worry about it.

it is nice to see photos with questions !!

#1 - the transom. You will probably recieve several suggestions
on how to tackle this one. You did not mention what size motor
you will be putting on the transom.
The wood in the boat transom was designed to prevent the rear hull from flexing,
thus popping fasteners and creating all kinds of issues..... Namely, the motor falling off.
the welded corner braces really throws a hiccup into your options for sure.

I think this comes down to how much you like this boat and how long do you plan on keeping it.
Compared to the amount of work it is going to take to get it right.
of course the first thought is to cut out all the braces and replace the wood. Then redo the braces.
to skip that step, a 1/4" aluminum plate securely bolted through the existing transom will help. (for awhile).
But due to the condition of the wood, it will eventually have to be replaced (perhaps by the next owner).
wow - what a pickle you have there !!

#2 - as for the mystery rivet - where is it and what does it hold down ??? more info needed on that.


The "aluminum brace" that you mentioned is called a knee brace.
it must be removed in the wood replacement process and put back.
yes, two more would be to your advantage to keep everything firm.
they can be found on e-bay as well as different boat parts suppliers.
or, if you have the means, make them yourself.

and I agree with 2smknbrls:
remove the knee brace and the flashing holding the bottom of the plywood.
remove all fasteners and try to wrangle it out.
the new wood must go back in the same way.
The Lone Star I am working on now has two cracks in the top cap worse than yours.
I plan to securely attach a 1/4"x1.5" strip of aluminum along the top of the new plywood transom and
it will slide under the top cap and give it that much more rigidity. That takes care of the top cap crack.
it would take a Sherman Tank to bend a securely fastened piece of 1/4" aluminum laterally. (so I trust it).
also, a new 1/2" plywood outboard mounting plate on the outside of the transom will help.
use the "search" feature as how to properly preserve, seal and waterproof the new wood.


this is how I reinforce a transom to minimize movement.









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Thank you for your responses. I don't mind taking the time to do this right. I do want to keep the costs reasonable. This boat does have some sentimental value, but if it's cheaper to find another than repair I would prefer to go that route. This would still make someone a great pond boat. I'd like to run something in the 9.9 to 15 for the engine. I'm open on that end.

The mystery rivet goes to a piece of wood that was added. You can also see the bend in this pic. The bend runs along the Z plate. The crack in the top of the transom also goes behind the wood about an inch.



Does wood have to be used? It seems like 1/2" aluminum plate would be much stronger and never rot. Would this be a bad option?

Johnny- I just saw the part about the boat you are working on. Have a picture of the crack? I had thought about finding a thick piece of aluminum angle across the top cap to add strength. Angle wouldn't have much more weight and be much stronger than flat bar.

Dan, here are two cracks in the top cap






This is the pneumatic metal saw that I have and
it makes quick work of cutting sheet metal.
available at HF and get a couple packs of blades.
(the one at HF does not come with blades).


the idea of a simple angle along the top edge will also work fine (for a temporary fix).
as for the rivets holding on the 1/2" plywood - just cut them off
and use bolts for the new one. yes, most any exterior weatherproof
material will work for the outside motor mount. Must be waterproof
as that item gets wet a lot while boating.

when I install the new transom board into my boat,
the reinforced top will take care of the cracks in the cap.
I may just put an angle on the top also just for cosmetics.
it will have a 1958 35hp Johnson pushing it - so the transom has to be right.



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Do you have a thread going on your boat? It would be interesting to watch. I wasn't thinking of the aluminum angle as a temporary fix. My thoughts were to drill the end of the crack on the top cap so it stops spreading, weld it up, and then grind it all down smooth. Then I would weld the aluminum angle across the topcap from brace to brace. I have never repaired an aluminum boat so I appreciate your input.

Your CAD drawing looks like you will be adding a piece of flatbar across the topcap where I would just use angle instead.

yes, welding is always the best repair method for most aluminum issues.
if welding is not an option, then, we use our best judgement as to the fix.

I do not have a thread on my Lone Star as it is turning into a nightmare. (well, bad dream anyway).
I just discovered that most - if not all - rivets are compromised by corrosion and
the seams are popping open easier than splitting a watermelon.
So I will be drilling out and replacing rivets for some time to come yet.
((I am talking about roughly 500-800 rivets)).
so that is job #1 - then, I will get on to the new wood furniture and painting.

BOAT = Break Out Another Thousand !!!





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Dan said:

Your CAD drawing looks like you will be adding a piece of flatbar across the topcap where I would just use angle instead.

Click to expand...

Dan, no, actually, the top 1/4" bar is securely fastened to the wood itself.
then, a layer of fiberglass on the top and overlapping the sides maybe one inch.

This particular transom will have a natural wood veneer on the inside strictly
for cosmetics. Then, the whole assembly will slide up under the factory top cap lip
and never be seen. Then, my thought goes to the angle on top just for cosmetics to
cover the imperfections in the factory lip. (the cracks and corrosion).
This is a family leisure cruiser - for show and tell - not a fishing boat.
but, the building fundamentals apply to any type of boat.

This is my current thought process.





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I had some time to clean things up and it looks like the transom bent from the torque of the motor. The wood will be easy enough to replace, but I would like to stiffen the transom up where the bend is. The easiest option would be to be to extend the wood down several inches and use stainless bolts to put it back together. Adding another knee brace would also be a good idea. Is there an advantage to having the knee brace attached to the floor instead of attaching to the back of the seat? I'm guessing the seat is a much thinner guage than the floor. I'm going to start tearing this down today and hope I don't find new surprises.

I think you are on the right track.

in my honest guesstimation, anchoring a transom to a seat is not a good idea.
it will also provide a kneeknocker and trip hazard when stepping over it. (if connected to the seat).
UNLESS - you plan to build a floor or deck up high enough and brace it to that.
if not, stick with the braces anchored to the floor.
if you feel that the floor is insuficient, place a 1/8" aluminum stiffiner under the brace.
size determined by your own thoughts.
try to stay 3-4" from the bottom of the boat for the new transom wood.
sometimes a lot of water will accumulate there and it could rot out the bottom of your transom.
fabricating the transom wood is a very hot topic here - just read the archives - use the search feature.

maybe I am wrong - there are several members here that have dealt with transom braces in the past.

one step at a time !!

I removed more of the old wood to get a better look at the transom. I feel like the prior owner ran the engine with a deteriorated transom that lead to the bend. My guess is he noticed the bend and had the corner braces added and welded the crack in the top cap. I'd like to repair this and know this isn't going to happen again. Below are some ideas I had. If anyone has tried something similar and it failed please let me know.

I should not have a problem extending the wood an additional three inches to cover the bend. Hopefully bolting over the bend ill help straighten it out.


Its very hard to capture the bend with a camera.




My thoughts were to weld down a piece of 1/4" aluminum angle shown by the green area and find a piece of 1/4" aluminum plate to weld in the area with the red lines.

Once you replace the transom wood I don't think the slight bend of the transom is going to affect the performance of your boat.

You are probably right. I may go ahead and extend the wood 3"-4". That will cover the bend and should stiffen it up.

I have been looking at pictures online of other transom repairs and noticed that many Jon boats do not have the Z plate at the bottom of the wood. Are these used from the factory to add structural strength? I believe I can add the support I want with a modified plate but I didn't find replacements available online. Anyone know the technical term for these? Maybe that's my search issue.

Dan, if you decide to use the Z-bar, my suggestion
would be to leave about 1/8" gap between the bottom
of the transom wood and the metal Z-bar......
so as not to trap water in that area that "could" wick up the transom wood.
trapped moisture between any two surfaces (wood or metal) may invite problems in the wood.

and as you noted, there are as many different techniques used to
replace the transom wood as there are flies on a dead cow.

when it comes time to actually cutting and fabrication of the wood, use the search feature
about "preserving" or "waterproofing" a transom.

good luck !!

Dantheman said:

I have been looking at pictures online of other transom repairs and noticed that many Jon boats do not have the Z plate at the bottom of the wood. Are these used from the factory to add structural strength? I believe I can add the support I want with a modified plate but I didn't find replacements available online. Anyone know the technical term for these? Maybe that's my search issue.

Click to expand...

The Z brace does add a lot of structural support. In the late '60s StarCraft went from 3 knee braces to 1 knee brace and added the Z brace to the transom.

Thanks for the response. The Z brace is not very thick and doesn't really look factory. I found Z aluminum but not many size options are available. There is about 1/2" bend in the transom. This is going to bother me and I do not want it to continue flexing.


My thoughts are to not use the Z bar, replace the wood, and use 2x3x.25 aluminum angle in the area shown below.


Then use a piece of 1/4" thick aluminum plate on the exterior area shown below that is the same width as the angle on the interior. Using stainless bolts across the top and bottom of the aluminum should clamp everything flat again and prevent future flexing. I figure I should go ahead and add the plate behind the motor if I am going this far. I can weld it to the bottom plate and shouldn't have a problem running a 15-20 motor.





Thoughts?

Dan, if you want to use the Z-bar brace, that will be fine.
looking at it, I also thought it was pretty thin metal.
to make a bracket that you want, weld a piece of flat bar
to the edge of a piece of angle aluminum.
The new wood will determine the open area of the Z-Bar.........
so if you want to go this route, make your new transom first
then fabricate the Z-Bar to fit your wood thickness.
of course you can use your choice of thickness aluminum: 1/8", 3/16" or 1/4".


jus my Dos Centavos