# 1973 AlumaCraft F7 - A Modified Overhaul In Central Florida



## Cagey (Jul 7, 2014)

A 1973 AlumaCraft F7


A friend of mine had this old boat laying in his backyard for a few years doing nothing with it and when I asked him about it he said I could have it. I learned the hard way why something free is not always a good idea. But, once I got into it I decided I was going to finish it no matter what.

This is my 3rd aluminum boat and I was ready to sell my other boat because apparently I was overpowering it with my Yamaha 25 outboard. That boat was a 1983 Sears GameFisher 14' jon boat with a squared off front and flat bottomed from front to rear. And when I would try and go full speed across a lake with any amount of chop, I could watch the bottom of the boat flex in and out and thought to myself one day that is just going to give way and I'll sink to the bottom. So I had been wanting to find myself a decent 14 foot all aluminum semi-V hull that would cut through the chop better.

So when my buddy said I could have the old boat and that he would scrounge up the title to it, I said what the heck. I had no idea what I was getting myself into. My buddy told me that he had the transom repaired and all welded up and that he had a 40 hp outboard on and it handled well with no problems.

When I approached the old boat laying out in the yard next to the woods, I noticed it had about 8 inches of water and mud inside and plants growing out of it and vines all over it, but it was free. I laid it on its side and rinsed it down and it looked OK. No real damage to speak of. It had plenty of dents I could pound out, but for free, I couldn't beat it.

So I hauled the old boat home and slowly began working on her little by little- out in the backyard at first. Looking more closely at the bottom I discovered the boat covered in barnacles. My buddy had let it sit in salt water for a few weeks before hauling it out into the yard where I found it. So that was the first thing to clean up was the outside of the hull and take it all the way back to bare metal. And get rid of that cheap rustoleum ugly old camo paint job he put on it for duck hunting up north.

I'll post the overhaul photos in sections...

But first I would like to thank all those nameless posts I read here about all their overhauls and the valuable information I spent hours reading here that helped me along my way. It definitely made a difference for me and I sort of developed a few rules along the way like a rule I follow about not using any wood in the boat for one. Only plastic, aluminum, and stainless steel materials.

And so it began...





An old AlumaCraft catalog image showing the same boat as mine.





Eugene Erich Swenson, the AlumaCraft boat designer shown here in one of his custom one of a kind creations back in the 1940's or 1950's.






These guys don't look as happy in their F7 as I am in mine!


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## Cagey (Jul 7, 2014)

My first job was to scrape and sand down the outside of the hull and remove thousands of barnacles and take it back to bare aluminum. And those little buggers were hard as a rock! Sanding was not working, so scraping by hand was about the best way to remove them. A long tedious job.











This is how the so called welded in transom repair my buddy had done looked when I got it. It was a piss poor job, not well thought out at all. And, if that was not bad enough the welds were crappy and the most important welds were all cracking from the stress he put on it with his 40 horse power outboard.

Also, notice in the image shown above how shallow of a draft this boat floats! Mere inches in the water! And that is perfect for me since I plan to only use this boat in fresh water lakes and rivers as long as I have it, and some of the places I fish are extremely shallow and this boat is perfect for all those backwoods places everyone else can NOT go!











I like an open boat and these pipes welded into the back corners of the boat took up too much space for me and I wanted them gone. So, after examining the transom repair he did I decided to rip it all out and start over and do it my way.


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## Cagey (Jul 7, 2014)

Showing the cracked welds in the crappy transom repair. Time to rip this junk out!






A 3/8" plate of aluminum across the transom and it was not even fit in tight to hull. You can see space between this plate and hull. Another reason it flexed and cracked the welds. Out it goes! I need a bigger hammer.











Now back down to hull only, and more room inside the boat! Now that's more like it. I can work with this now.

And this is when I ran into a situation with the transom knee. I knew something was going on underneath it when I saw this kind of separation from the bottom of the boat:






I found quite a bit of corrosion underneath and had to remove the transom knee along with the crappy old transom repair. Man this thing is turning out to be more work and expense than I had originally thought.


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## Cagey (Jul 7, 2014)

I use to work in a sign shop and we did metal fabrication every day. So I had no hesitation in doing my own repair of this transom and I wanted to do it in a way that would not need any wood, would not need any plastic. And I would not do any welding. And I would do a complete repair and a very solid job of it using only two pieces of aluminum I purchased from a local ALRO Metals company.

The first thing I had to do was to make myself a template to work from. I would not cut any metal until I was certain that my template was a perfect fit to the back of the transom:






Once I had that perfect fit, I transferred the pattern of the template to a 1/4' thick plate of 6061 aluminum and cut it by hand, and I even cut out a window or hole to allow government officials to see the boat's original hull numbers stamped into the back of the transom.

Before I cut the aluminum, I made sure to reduce the template size to a bare minimum so as to cover every hole in the transom to seal the boat up, and to connect to the three points, two up top on each corner, and then at the bottom this 1/4" plate is directly connected to the transom knee which transfer thrust directly to the keel along the bottom of the boat. My forward thrust is evenly distributed to all three points and rock solid.

I got my grinder out and cleaned out the underside of those rear corner handles and purchased from ALRO a 1-1/8" square rod to go across the top of the transom on the inside of the hull and it fit perfectly up into those corner handles now cleaned out, and one bolt down through them actually acted like a hinge and would now pivot a little and give a little with the thrust of my outboard. No welds to crack. It is a solid transom now, probably 3 times stronger than it was new from the factory. Worked like a charm!

And I used 3M 5200 marine sealant to attach the new transom plate to the back of the hull and bolted it down with 5/16" aluminum nuts and bolts.

The photo below shows only the first few bolts I used to get the plate in place for fit purposes. Later on you will see the finished repair with more bolts installed, including down at the bottom where it is attached to the transom knee. I was intentionally avoiding where the outboard was to be installed because I did not want any bolt heads to interfere with the installation of the outboard- and you can see the square box I drew in on the template where the outboard would be. I wanted to make sure my bolts also did not interfere with placement of a trolling motor too. So that is why there are no bolts across the top yet. Just planning ahead is all.






And it was about this time I went over the boat examining all of the rivets. I knew darn good and well I was not going to drill them all out and replace them all. I was not going to try and hammer them all tight again. So I drilled out any bad rivets and installed 1/4" aluminum bolts and aluminum nuts, cut them off and sanded them down and I used thread lock on them as well. And now I don't even notice them. No leaks and stronger than the original rivet.

I purchased all of my aluminum hardware, including the aluminum nuts and bolts I used in the transom repair from Non-Ferrous Fastener, Inc. https://www.non-ferrousfastener.com/


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## Cagey (Jul 7, 2014)

I like a clean boat inside. And this old boat had one hell of a large cavity up front that filled with dirt and water. So I cleaned it out and filled it with epoxy as shown here. Now no water can get in or out and all water and dirt washes out easily now.

You can also see a couple of the rivets I replaced with 1/4" bolts in this next image.











The boat is now getting closer to painting as my grandfather is doing the masking tape on the top rail I wanted to keep natural aluminum. And if you look closely you can see the rod installed across the top of the inside of the transom now and bolts sandwiching the hull in between the rod and 1/4" plate on the backside of the transom. And now there are only three holes in the transom- two to bolt the outboard to the boat, and one drain at the bottom. Other than that, she is sealed up tight now.






That gallon of paint sitting up there cost me $92.00 plus shipping. And I would like to thank Paul Oman of Progressive Epoxy Polymers, Inc. for all of his awesome advice and suggestions on painting and prepping the aluminum surface. I decided to go with their ALUTHANE moisture cured urethane for two coats of primer paint on the boat inside and outside.

Website: https://www.epoxyproducts.com/

They have an incredibly informative website that I spent hours on reading and learning, and I am grateful that Paul responded to all of my questions and answered all of my emails and even wrote to me after my purchase to see how it was coming along and if I needed anything else- and who does that these days? Great service and a great product! ALUTHANE is awesome! It went on real easy, covered well, and flowed into cracks and crevices sealing up any leaks if there was any I never found out. Not yet anyways.











Grandpa is working on the masking tape on the top rail. And we are preparing to paint the outside of the boat now with two coats of ALUTHANE











This is what it looked like with the ALUTHANE paint. Now you can see all the bolts used on the new transom plate. It is not going anywhere. I bet I could take those bolts out and the 3m 5200 would still hold it in place.


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## Cagey (Jul 7, 2014)

So this old boat has two full coats of ALUTHANE inside and out. Next, I wanted to really put something tough on this boat. I wanted to make sure it was sealed up with no leaks and I literally painted on next two new hulls, one inside and one on the outside. So I went with a super high quality industrial epoxy made by Sherwin Williams that I found on craigslist for like $50.00 for 2 full gallons.

I wanted an epoxy that had some flexibility capabilities to flex with the hull, as well as super hard scratch resistant properties too. This epoxy is used on water towers, bridges, industrial plants, etc. so it was some tough stuff! I put two coats on the outside of the boat covering every inch under the top rail, and on the inside of the boat I only put it on up to the bench seat brackets well above the water line as shown here:






Epoxy on top of ALUTHANE. Now I am up to 4 coats of paint inside and out.

I forgot to mention this so I will add it in here... I was advised that once I was finished with the epoxy to then go back over the epoxy with one or two coats of ALUTHANE since it sticks to epoxy better than the enamel does. So that is what I did, and then applied the top coats.

My buddy the previous owner had installed some oar lock brackets using rustable steel nuts and bolts and it caused galvinic corrosion eating through the hull around the washer. So after painting the boat with a white industrial enamel, I reinstalled the oar lock brackets using all aluminum hardware this time, including some custom made aluminum washers I made myself to cover over the hull damage:











And finished it up to look like this, and sealed these up with 3M 5200 marine sealant.











I had to sit the freshly painted boat outside on the ground while I modified and adjusted the trailer to fit this boat. I had to take the axle off and drill out the frame and move the axle and suspension back towards the outboard because I am using a hefty 2003 Yamaha 25 4 stroker and it made the back of the boat so heavy it was out of balance. So moving the axle and suspension back was my only solution. I also had to install new skids under the boat and move around some of the rollers to fit this boat.





Freshly painted with a Sherwin Williams gloss white industrial enamel.


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## Cagey (Jul 7, 2014)

Now it is time to do some inside the boat work.

I like an open boat inside to walk around in. I do not like to step on and over a bunch of benches. I know they had foam inside for floatation once upon a time, but this boat is now 41 years old and most of the foam had melted or rotted out and was useless, so I did not need the benches for floatation. Besides, it is not like I am going to use this boat in deep water. Most of my boating and fishing in central Florida's lakes and rivers is 8 feet deep or less. Not a real concern to me. I have never sunk a boat yet in more than 30 years and I don't plan on it now. So the bench seats are NOT going back in. Those are getting painted and put into storage for possible future use if I sell this boat.

And some would say I needed the structural strength those benches provided. So I wanted to add a front casting deck and I used the old bench seat brackets as my location to begin building an all custom made solid aluminum frame. And I let the new casting deck become the structural strength that the benches provided previously.

I had one issue I needed to solve with this plan and that was when you step up and down from the deck to bottom of the boat, I did not want to stress the one rivet on each side of the boat on the bench seat bracket. That would not have lasted no time at all. So I devised a plan to extend the casting deck about 8 inches further back and install some hefty custom made "L" shaped hanger bars which are bolted to the top rail and extend down to the deck level without touching the hull so there is no wear or vibrations there, but now I can step up and down for years to come and never have to worry about wearing out the seat bracket rivets which were not made for that kind of weight and stress. And this gave me 8 more inches of casting deck too!

And I wanted to add in a casting seat on the deck, so I used some spare 1/4" aluminum plate I had left over from the transom and once the cross members were installed I bolted a 10 inch wide plate across all three cross members and raised it up with a 1/4" plastic spacer to give it a half inch thick rise so when I installed my half inch thick expanded PVC decking, the seat plate would match the height of the deck and once covered in carpet you would never know it is there.





These hefty hanger bars are each custom cut and custom hammered into shape differently for each side of the boat designed to take the full weight of a man stepping up and down off the casting deck without damaging the flimsy rivets in the bench seat brackets. This image shows the aluminum bolts attaching it just under the railing before I cut them down and sanded them.






I have another template cut and ready for the pedestal seat base to be installed next.


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## Cagey (Jul 7, 2014)

Here is the finished deck, with carpet added. The deck was done in 3 sections and the middle section has aluminum hinges and aluminum hardware and can be opened from the boat to access under the deck where I put the 6 gallon gas tank and the battery is also under the deck. I left it open in the back for more access and to also allow gas fumes to vent out. And I had to raise the pedestal a few inches and simply cut some blocks out of expanded PVC and stacked them to raise the seat to the right height.

And now we are ready to roll!











I am not completely finished with the boat, but she is in the water and we're having fun with it. I am adding in two terminal strips, one in the back of the boat and one in front under the deck by the battery and 10 gauge wire positive and negative run between- keeping the electrical floating above hull/chasis. And when that is done, I can add another trolling motor in the back, I'll add in a bilge pump even though I have not needed one yet and there is not one drop of water getting into this boat- except for what flies in over the railing.

And I am adding a rectifier to my outboard and will be able to charge my battery when running the Yamaha. I've added a Lowrance GPS/twin sonar/mapping fishfinder.






In order to fit a trolling motor on the front of this boat, I was not able to get it mounted on the top rail, so there was already 4 holes drilled into the bow plate by previous owner for a light and I used those same holes to make a bracket out of plastic to hang the trolling motor just outside the boat, but now level and square and solid.











Looks like my little first mate has had it and sacked out on me ready to call it a day. Me too.


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## Cagey (Jul 7, 2014)

Top speed in this mercury test is about 20mph.

My Yamaha 25 will push this boat well over 30mph now. And that two-piece transom repair is rock solid now. No problems at all.

My new 41 year old boat is not like grandpa's!











Total cost on hull around $500.00 finished.


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## Stumpalump (Jul 7, 2014)

After 41 years all it needed was some love. Nice job. Do you have any plans for floatation foam under the seats or floor? If not tie a throwable device or milk jug to the hull with a rope long enough to float to the surface. Safety freaks will say it's for safety but I'd be more worried about not finding such a nice boat in 8' of murky water.


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## Kismet (Jul 7, 2014)

Wonderful write-up: clear, detailed, and instructive. 

Great job on the watercraft, as well.

With the fuel and battery up front, I'm guessing the weight of driver/motor is nicely balanced?

How stable is the person riding up front when you are making speed? Does that seat lower?

Very clean resurrection. 

_(and the trailer...smart work. I'm inclined to forget trailer work and have regretted it.  )_


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## Cagey (Jul 7, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=358568#p358568 said:


> Stumpalump » Today, 10:42[/url]"]After 41 years all it needed was some love. Nice job. Do you have any plans for flotation foam under the seats or floor? If not tie a throwable device or milk jug to the hull with a rope long enough to float to the surface. Safety freaks will say it's for safety but I'd be more worried about not finding such a nice boat in 8' of murky water.




Thanks for the compliment. I have thought about the flotation issue.

I am considering adding some under the deck and rear seat. But I confess the rear bench was just a quick fix to get it in the water. I'd like to eventually design and build some type of a seat frame that can be removable and lock onto the top rail and then sit on the bottom of the boat too. I wanted to be able to walk from stern to transom without climbing over benches and that goal has not yet been acheived.

I wonder if I could use a sealed box, container, or something that would float as part of the rear seat design. But that is down the road for now. Under the deck is the only space available for adding in some type of flotation materials.

The deck itself, rear bench, and seat blocks are all expanded foam PVC and all of that floats! But it is not enough to keep that Yamaha off the bottom right now if it were to sink.


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## Cagey (Jul 7, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=358638#p358638 said:


> Kismet » Today, 11:48[/url]"]Wonderful write-up: clear, detailed, and instructive.
> 
> Great job on the watercraft, as well.
> 
> ...



Thanks! And yes the boat is now very well balanced with fuel tank and battery up front, and you might have noticed the trolling motor is on the opposite side from the rear driver's seat which also helps to balance it out when it is just me in the boat.

The front seat is very stable because of how I mounted the base on a large aluminum plate across the 3 cross member braces, and the rear bolts of the seat base go through the plate and through the center cross member and is real solid. It is not going anywhere. And that particular seat pedestal does not lower. It is a fixed pedestal. I may change it out down the road, but I had two of these on the shelf and just used one of them out of convenience. It is not ideal but it works.

But the problem is that seat spins real easy and if someone is sitting on it and I am going full speed, they could spin off it and could be hurt, so for now believe it or not, I have added a seat belt for anyone insisting on sitting up there going full speed. Usually they either sit on the bench next to me, or sit on the edge of the deck for now. I am considering adding in a removable rear facing seat which will sit on the bottom of the boat and either bolt up or clamp onto the deck cross member.

In Florida if you want to tow anyone behind a boat on skis, or wakeboards, etc. you gotta have a rear facing lookout besides the driver, so that is on the list.


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## Cagey (Jul 7, 2014)

I received a message from someone wanting more details on how I made the connection of the new transom parts to those top corner handles.

The key was in putting in a thick-walled aluminum rod across the top that goes inside those handles underneath them. I cut the rod off about an inch or so inside the handles and then did a angle cut on the ends so that when I do a hole shot from zero to wide open and maximum force or thrust is pushing forward, the new aluminum plate with hull sandwiched in between it and rod can flex or bend a little bit and the way I put a bolt down through the handles and through the rod actually works like a hinge and will give with the flexing of the new transom. So here are some closeups of the top of the new transom.

Keep in mind my repair design required only two pieces of aluminum and is very simple, very straightforward and very strong. Much stronger than it was when new back in 1973 when they recommended no more than 16 HP for this boat. I could probably put a 75 on it now with no problems other than going faster than the boat was suppose to go. I think my 25 is about the maximum I would want to go though I would like just a touch more top end out of it and am considering installing the brand new carburetor I have from the 40 hp to see if it will get me there. If not, I will just have to be happy with this 25 as is.

One more thing... This transom rod across the top is the only place I used steel bolts. I was not sure if the aluminum bolted down tight would pop if the top flexed so I just went with steel for strength and later on I might replaced them with stainless. Not sure if I would ever try aluminum for this purpose.


























See how I got that rod up into the underside of those handles? The forward thrust is solidly connected to the rest of the boat right there as well as just beneath the outboard to the transom knee. It simply can not be any more solid than this in my opinion. And I did not lose any room in the boat like the previous transom repair and with no welds, nothing to break! Last forever I hope. So far 6 lakes and two rivers and no problems.

This simple transom design of mine is relatively cheap and easy to do and quick. And it can be done on just about any AlumaCraft with similar transom design. And the nice thing about it is, it is permanent. The boat will probably fall apart before that transom does!


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## bthompson92 (Jul 7, 2014)

Great job on the build, looks great! On the transom did you use stainless steel bolts sealed with 5200? How has it held up?


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## Cagey (Jul 7, 2014)

[url=https://www.tinboats.net/forum/viewtopic.php?p=358685#p358685 said:


> bthompson92 » Today, 16:37[/url]"]Great job on the build, looks great! On the transom did you use stainless steel bolts sealed with 5200? How has it held up?



Thanks! I used 5/16" aluminum for the transom plate except for the bar across the top. Right now I have steel bolts only across the top and may switch to stainless. And yes, I used 5200 on them and the entire face of the plate too. I could probably remove the bolts at it would still stay in place. That 5200 is some sticky stuff that won't come off. It is holding up great so far. Strong as heck too.


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