Transom Restoration on 99 Starcraft Superfisherman 176

[muskyhunter1978]

Hello everyone. First time poster here.

I have some questions I'm hoping the experts on here would be able to point me in the right direction or affirm that I"m headed that way. I got a killer deal over the summer on a 99 Starcraft Superfisherman 176. The boat hull is perfect, hardly a mark or ding on it. Carpet, seats, everything is in very good shape for its year. The issue that I found on this boat is the transom. There are about a dozen spots where its corroded completely through. The previous owners had a boat shop patch them with some epoxy type of stuff, which is holding fine. The boat takes on no water. All of the spots are where the wood inside is in contact with the aluminum. I spoke with a boat restoration place and sent them pictures. They indicated this wasn't uncommon for that boat and year and said it was from the wood being treated reacting with the aluminum. They wanted 3K to repair it, but I'm handy and have restored a few other boats in the past. First transom however.

Here is my plan. I have already begun the disassembly of the rear of the boat. Motor is off, back deck removed and the top cap is off. I am going to remove the splash well, and other aluminum that encloses the transom wood. I will then pull the wood core out, using it as a stencil to make a new core from non treated plywood, then put a couple of coats of epoxy to seal it. My plan is to fit it, drill all of my holes, then pull it back out and redrill the holes a bit larger so I can full encapsulate each through hole with resin as well.

As for the aluminum. Once I have access to the backside of the transom aluminum, and provided it don't look too terribly bad, I will clean up the pitting with an angle grinder, wire brush, etc to remove as much of the corrosion and oxidation as possible. Then I will give it all a good cleaning with an acid etch to further ensure the corrosion is gone. After this, my thoughts are to chemically bond a 1/16" thick sheet of aluminum to the backside of the transom skin. I watched a video of a gentleman that did this process and he seems like he does very good work. He used a product called GFlex epoxy which sounds like it has very similar properties to the glues they use to attach body panels to cars. Tough stuff. This will strengthen the tin and most importantly completely seal any of the corrosion holes that are all the way through. After this, I will use the epoxy on the outside to seal up the holes from the outside as well. My understanding of corrosion is that once you remove oxygen from the equation, it can't do what corrosion does. Then, sand, prime and paint the outside. I should be then ready to reassemble the boat.

Its a great boat and really like fishing off of it so far. I'd like to rebuild the transom for now, then upgrade/work on other parts as I go. Seems like the boat has a lot of life left in it.

Thoughts on my plan?

 

[LDUBS]

Welcome to TinBoats. That is a really nice boat - congrats.

I need to provide the following disclaimer. I'm not an expert and have not done what you are talking about.

The video I saw the guy epoxied skins on both the inside and outside of the transom. I kind of like your idea of putting the skin just on the inside. The video I watched, when the guy put the skin on the inside, epoxy oozed out all of the holes in the transom. When it partially set up, he scraped it flush with a putty knife. Pretty cool. I think I would paint the outside of the transom to protect the epoxy from UV rays. Maybe GFlex doesn't have this issue, IDK.

Keep in mind the existing top cap will need to fit over the two layers of aluminum + your new transom wood.

I think the way you describe doing the new wood transom holes would be considered a best practice.

I hope you circle back with some pic of progress on your transom rebuild.

 

[Billy H]

I’ve done transom replacement with wood on boats I’ve sold. If I had to do another one on a boat I planned to keep I would 100% go with an aluminum replacement transom.

 

[muskyhunter1978]

Welcome to TinBoats. That is a really nice boat - congrats.

I need to provide the following disclaimer. I'm not an expert and have not done what you are talking about.

The video I saw the guy epoxied skins on both the inside and outside of the transom. I kind of like your idea of putting the skin just on the inside. The video I watched, when the guy put the skin on the inside, epoxy oozed out all of the holes in the transom. When it partially set up, he scraped it flush with a putty knife. Pretty cool. I think I would paint the outside of the transom to protect the epoxy from UV rays. Maybe GFlex doesn't have this issue, IDK.

Keep in mind the existing top cap will need to fit over the two layers of aluminum + your new transom wood.

I think the way you describe doing the new wood transom holes would be considered a best practice.

I hope you circle back with some pic of progress on your transom rebuild.

Thank you for the reply. You and I are talking about the same guy on Youtube, Team Reelin' the Blues. After quite a bit of research on this topic, I feel like his way is the most sound of options, maybe even overkill. Now, I haven't gotten it all pulled apart to see the extent of the damage, but as of now, I don't have nearly the holes he started out with. This is what is intially leading me to just use a thin sheet of aluminum on the backside to fully seal it up and also arrest the corrosion.

You commented about the two layers of aluminum and the cap fitment. I'll absolutely check this. My guess is a 1/16 of an inch, I can "fudge" the caps a little if needed to make it fit.

My plan after its all done is to sand, prime and repaint the entire transom so UV won't be an issue. As I said, I'm not looking to sink thousands into this thing and just want a nice serviceable boat for a while. I know me, I'll be on to another boat in 10 years... lol.

Here's a couple pics of this thing. For an 01, she's in darn nice condition.

 

[muskyhunter1978]

I’ve done transom replacement with wood on boats I’ve sold. If I had to do another one on a boat I planned to keep I would 100% go with an aluminum replacement transom.

Its definitely quite a lot of work. I don't have access to a welder and local places quoted me a couple grand to replace the skin all together. However the boat restoration place I talked to said to be very careful with welding if the weld needs to be close to the rivets because of heat. They told me they'd much rather completely remove the rivets and replace it, which is also several grand. I didn't pay much more for it to begin with... lol.

 

[Billy H]

It’s definitely quite a lot of work. I don't have access to a welder and local places quoted me a couple grand to replace the skin all together. However the boat restoration place I talked to said to be very careful with welding if the weld needs to be close to the rivets because of heat. They told me they'd much rather completely remove the rivets and replace it, which is also several grand. I didn't pay much more for it to begin with... lol.

I was referring to prefabricated transoms like these.
https://tbnation.net/products/trans...GCxn5kmxIWncyBNmOsaOPFbXjm3CM4rsaAolxEALw_wcB

 

[airshot]

Sounds like you have a plan...nice looking boat !! Can't believe there are issues already, being a 99. Looking forward to your repairs, post lots of pics !! My 1992 Sylvan is all aluminum in the transom, but floors and decks are carpet covered plywood, but so far, still solid. Good luck !!

 

[mirrocraft16]

About 12 years ago I had a 1999 196 Super fisherman that needed a transom, and some other work as well.
It had belonged to a buddy who had inherited it from his brother. I had bought it for its motor, but ended up deciding to keep the boat and do the repairs.
The transom was rotted in three spots, both upper corners near the corner caps were perforated, and a spot almost dead center on the left side right at the water line had pencil sized holes poking through. Plus it had a dozen or so rivets that had popped off.
I gutted the boat completely to assess the situation and almost hauled it to the scrap yard at that point but for some reason didn't. I kept telling my self that no matter what i ended up having to do, it was cheaper than buying a new boat, or even a turn key used one. The motor was a good runner, and the interior was like new, and it was sitting on a near new trailer.

I gutted the hull, removed all the pour in foam, replaced a ton of rivets, then after some thought, cleaned up what was left of the outer transom skin, coated it with self etching primer, made an inner skin from a sheet of fiberglass, and poured the transom top to bottom using Seacast. Once it was all set up, I sanded and repaired the exterior using Marine Tex epoxy and some fresh paint.
I rehung the motor, cut new custom foam blocks instead of poured in foam, replaced the decks with 3/4" plywood coated in fiberglass and epoxy, some new carpet, and it was good.
I kept it for about 8 years. I sold it after deciding it was too big for the small ponds here and too small for the saltwater. A buddy still runs it today.

In hindsight, I should have just kept the motor and sold the boat, but the repair was the right choice in that it'll likely last forever. The original wood and foam in those boats must have been corrosive. It seems everyone of them I see has holes through the transom, most are at the top corners and around the sides of the motor.

Mine also needed a ton of rivets replaced, after finding a few missing up front, I started tapping on them all with a mallet and found over 200 that just sheared off. I basically replaced all that were below the water line.
It also had outer perforation on the bow, at where the foam ended and met the wood floor, just ahead of the consoles on each side. I ended up making up two 6x10" patches and I riveted them in place with epoxy sealer in between. The boat seemed to have corrosion anywhere near any of the wood and any of the pour in foam.
The foam was a mess, it was water logged in areas and felt like I was removing blocks of concrete. The hard part was getting it off the aluminum where it was still adhered. (That and hossing the 100lb chunks over the side).

 

[muskyhunter1978]

As I'm scrubbing, removing the corrosion from the pits, I'm starting to rethink one of my original plans. The plan was to bond the new metal to the inside of the transom skin. But, after getting some of this cleaned up, the pitting is rather rough in spots. So much so that I'm thinking it might be best to prefill some of the pitting with epoxy and letting it cure, before I bond the new skin in place. However, I'm beginning to wonder if skinning the outside of the transom is a better option as its perfectly smooth, aside from a few holes. I feel like I would get a tighter more uniform bond to the outside. If I go the outside route, I could then seal up the pitting on the inside, then paint the entire thing in por 15.

thoughts?

 

[LDUBS]

My initial reaction is put the new skin on the inside. Reason being the edges around the perimeter of the new layer will have some protection, and the part below the waterline will not be constantly submerged.

Additionally, If pitting on the inside is a concern, seems it will be filled in and sealed by the adhesive you plan on using to adhere the new skin.

Again, not an expert.

 

[hoarder]

Back in 2007 I bought a Superfisherman 196 that was listed 'For Parts Only'.
The boat looked brand new, but I was told the hull was no longer seaworthy and could not be fixed.
I got it at auction for $400. I was mainly after the motor, a minty clean 115hp Mercury, and the then 2 year old Load Rite roller trailer. For what I paid I wasn't expecting much but knew that in the worst case I could get my money back parting it out I bought the boat knowing that they had issues with corrosion due to the use of pressure treated plywood in those years and that the boat had thumb size holes in the transom up near the corner caps, and about dozen screw holes in each side of the hull from the inside outward.
The interior was minty clean, the engine was perfect. The first thing I noticed inside the boat is that the front floor panel had been replaced and the carpet there had glue on the edges. I pulled up the front seats and front floor and found two huge chunks of the foam dug out and there were two 10x20" pieces of plywood screwed to the hull on the inside, with deck screws from the inside out. There was white urethane sealer squeezed out around the edges.

When I removed the screws, the wood wasn't bonded to the aluminum at all, and I could see severe corrosion on the hull. The surrounding foam was soaked, when I chopped out a huge chunk to look at the hull further it weighed about 30 lbs, as I scrapped the foam bits of that area I could see the hull was eaten away bad where it touched the foam. When I stripped down the transom area it was worse, the hull skin was rotted everywhere, about 1/3 of the foam was water logged, and there were huge sections of the transom corrode so bad I could poke holes in the metal with a dull screwdriver.
At that point I just cut my losses and listed the hull the way it was and let someone else deal with it.
I left it all apart so whoever bought it could see the damage. I listed it as "Parts or repair' with no motor, no trailer, and no electronics or gauges for $2k OBO. It was gone in 2 hrs. for $1,500. The buyer was unfazed by the corrosion. (Two weeks later it was back up for sale on CL for $5,500 with a 30 year old electric shift Evinrude on it, listed with no title, it stayed listed for a few months, then it turned up the following spring for $500, with pics of the hull completely gutted and laying on its side with a chunk of plywood bolted over the whole transom and a half dozen or so screwed in place patches all over the hull. It had a title when I sold it.
I used the motor from that boat for two seasons and sold it for $1,500 and sold the trailer a year after that for a grand.
I've looked at others since and all had the same corrosion in the transom.

 

[thill]

I think Seacast is an excellent choice for that situation. It will fill and seal the interior completely, bond and greatly strengthen the exterior, and as you stated, it will last forever.

I need to remember that, next time I find a boat like that one. Thanks for sharing that.

Muskyhunter - that is an option you may want to consider. Thousands to weld some spots sounds like blackmail to me. If you lived near Virginia, I could hook you up for a few hundred bucks. That might be a "go jump in the lake" price because they don't really want the work/liability.

Sounds like that model of boat has some design issues.

 

[muskyhunter1978]

I think Seacast is an excellent choice for that situation. It will fill and seal the interior completely, bond and greatly strengthen the exterior, and as you stated, it will last forever.

I need to remember that, next time I find a boat like that one. Thanks for sharing that.

Muskyhunter - that is an option you may want to consider. Thousands to weld some spots sounds like blackmail to me. If you lived near Virginia, I could hook you up for a few hundred bucks. That might be a "go jump in the lake" price because they don't really want the work/liability.

Sounds like that model of boat has some design issues.

The only issue here is that the transom isn't sealed to allow a poured core. The only option I see here is something like Coosa board for a composite and they aren't getting 700 dollars from me

 

[muskyhunter1978]

Update time.

I got quite a bit done recently and hoping to start assembly in the next couple weeks. The weather is finally improving and I'm hoping to do the epoxy work in a couple of weeks if I get a couple of warmer days above 60.

All metal fab is completed with the exception of a minor trimming of the inner skin that is off a little for some reason. The skin that will be epoxied on the inside has all holes drilled and cleaned up. I figure I may as well drill them all and I can use them for clamping pressure with some bolts and blocks of wood where I need to. I decided to take blacks of pre drilled 2x4's, put them where I need to clamp and then numbered them all so I know exactly where each goes and I'm not wasting time getting it all clamped tight when it comes time.

I've spent quite a bit of time test fitting everything. Since I'm adding a shade under 1/8 of total thickness of metal, I wanted to make sure everything fit properly. One area I was a bit concerned with was the top cap of the transom. The top cap actually fits better than factory now with the additional thickness. its super snug and with a top of a rubber mallet, it seats nice.

Waiting on my epoxy to show up tomorrow. I'm going to get all of the mounting holes in the wood drilled and then over drilled in preperation for sealing. I got the gallon kit of epoxy resin, so I'm going to give the whole thing a coat, then when its dry, tape off one side and fill each bolt hole, allowing it to cure, then redrilling once set back in the boat.

I found a couple other areas on the hull toward the back of the transom in the knee area that are a bit concerning, so while I have it apart, I'm going to clean and repair those while I wait on the weather. Any luck I'll be fishing by april barring I can get the motor to run right (thats another project.. lol. carbs need cleaned).

The only area of question I have is paint. I can't decide what color of white this is and I don't really see the need to perfectly match it. Its not a bright stark white, but more of an off white color. As long as I can find a shade in spray paint that matches close enough, I'll be happy.

Attached are a few pictured of rough fitting everything.

 

[thill]

Looks really good.

When I was looking to paint my transom repair last year, I did a bit of research. I found that Rustoleum makes some excellent products.

First, they have Aluminum Primer in a can. I've used this for years, and it's excellent. Bonds strongly and prevents corrosion. A must-do. Wipe down with Acetone to de-grease and spray a dust coat, let it flash, and then two wet coats, allowing excess solvent to evaporate in between coats.

For the top paint, Rustoleum Industrial metal paint with a touch of Japan Drier (a hardening/accelerant) and a touch of thinner made for a beautiful, tough finish and can be tinted to any color you want and is readily available.

I posted a thread somewhere about it, including the video that I got the recipe from, but it's pretty simple. Add a capful of Japan Drier, stir the paint carefully, and then add a bit of Acetone to thin to the right thickness. Drop it into a cheap, Harbor Freight HVLP spray gun and go at it.

The trick to a beautiful finish is nice, thin coats. On a warm, dry day, wipe it down with Acetone to degrease, then make the first coat a "dust coat" where it's almost powdery looking and you can see through it. Let it flash for a couple of minutes and then do a thin "wet" coat that shines. Wait 5 mins, and then go with another and another until you are happy with the finish. Just make sure excess solvent flashes off between coats. Maybe 5 mins, maybe 10. I think I put on about 5 coats on mine to give a nice film thickness.

It goes REALLY fast. Spraying my transom inside and out took maybe 2 mins per coat. And what's cool, is with the Japan Drier added, it's dry to the touch within an hour, and hard by the next day.

I made mine off-white, too, although hard to tell in my pics:



The end result was excellent. The materials, including the gun were inexpensive, and the paint is holding up really well, as I knew it would. Hard, almost like plastic.

Rustoleum Industrial has always been tough paint, but it takes forever to dry and harden. Using the drier, Acetone and spraying it is a game-changer!

Way to go on your project, and keep up the good work. You will be on the water soon.