Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Boy, that sure looks familiar! So much of your boat looks like mine... I'll be interested to hear if your floatation foam is dry in the forward end of the compartment. With luck, it will just be damp in the rear by the transom. Keeping my fingers crossed on your behalf...

Personally, I don't know that cutting the stringers at an angle would make much difference. After glassing in with several layers of 1708, my stringers are super solid. Also, I don't think you can cut them on too much of an angle without getting close to the motor mounts. I tried to stay as far away from the mounts as possible, while still leaving enough room to get the new transom in.

My stringers were thick enough in points that a multi-tool would have had a hard time cutting through. I used a Sawzall, too.

Looks like you're making some good progress!

Jim

 

[Jammer864]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

In regards to the oil in the bellows from filling your drive. There is only one seal up there that would allow oil to flow into the bellows and that is around the input shaft behind the u joints. When you get time, you need to pressure test your drive and see if its leaking. There are basically 3 areas it can leak at......input shaft, shift shaft, and prop shaft. The Volvo forum has a sticky on making your own pressure tester, as well as how to test it.

Your flapper valve is missing a rubber bushing(s) that centers the "axle shaft" in the big hole in the side of the exhaust tube. Remove the flapper valve, file down the edges on the holes where they have deformed, get some new bushings, and reassemble. Make sure the rubber boot that joins the down tube to the exhaust pipe covers the bushing hole completely. Volvo Penta has a Service Bulletin to remove these flapper valves on some installations. Check and see if yours is included. In which case just remove all the parts and silicone the holes shut.

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Well got some more done today. Removed all the carpet from floors, locker and some on the sides (thinking of leaving the rest), about 2/3 of the transom wood and the back stringers. I found wet foam in only one location, inside the starboard stringer. The stringer is a foam filled large fiberglass stringer with no wood. Honestly, I'm not considering chasing it up the stringer any further. What I am considering is building some type of cut-off in the stringer before re-installing to prevent any moisture in working back into the new transom. Bad idea? Also, since the rest of the decking appears very rigid and no wet foam was encountered outside the stringer I am planning on leaving them in place.

For finishing, I'm contemplating cleaning up the deck and gelcoating.

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Looks like you're making progress. I wouldn't lose a lot sleep about the foam in the stringer... the foam isn't structural, and I'd think you'd be better off keeping water out of there. Your stringers aren't going to rot.

Did you find the layers of your transom plywood weren't even glued together? When I pulled mine out, the two layers of plywood were held together with only stapes, no glue.

What are you doing with your deck? Gel coating and snap in carpet?

Jim

 

[jsturvey]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Dude, that is a beautiful boat! Is that a 206LXI, or a 226LXI? I was looking Larson like this when I was boat shopping a couple years ago. It's easy to see why people hang on to those boats.

I think gel-coating the deck would be a great direction to go. Would definitely make clean up easy after uses, and would bring the boat more up to date, plus it wont retain water for long periods of time like carpet will. Also, kudos for that engine and outdrive stand. That's a nice one! Keep up the good work! Subscribing.

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Jim, I'm not concerned with anything inside the stringer rotting, but I don't want that moisture to work its way back into my new transom. Do you think I should be concerned after all the fiberglass that will be on top of the transom when its done? Also, did you find what appears to be half of a 4" dia cardboard tube that was used as a mold (to reinforce?) the top of the stringer. I managed to miss it on the port side, but got a good chunk of it on the star side.

Also, yes I did find the pesky staples. On one hand I was saying shame on you larson the next minute I was thanking them cause it allowed me to almost pull out the the first layer in one piece. Whats your secret to getting the rest of old transom out? The good stuff is taking me forever. Right now I'm using a rather wide chisel and just working my way across.

I haven't really thought about what I'm going to do with the deck yet. Other than "no carpet!" Okay I might think about some snap in in the future, but for right now I hoping to just CSM the deck and might just leave it like that. With the kiddos and all the spills, fish crackers, etc, I'm thinking this is way to go for at least the near future.

Jim, are you building supports similar to friscoboater for your bolsters? I've been toying with the idea of something like he did only in a circle.

jsturvey, its the 226 and thanks. I found in down near Houston about 1 year ago. Besides the transom, the boat has been a pretty good purchase. The only thing I had really done to it was add electric brakes to the trailer. Also, this is my first duo-prop and I love the bite I seem to have at about mid RPM's. But, I seem to have lost some low speed maneuverability.

Jammer, thanks for the input on the flappers and the o-ring. The flapper shaft have worn a nearly .75 in long hole on the port side and about 0.5 in in the star side. I'll try and find that service bulletin and hope that just get them welded up (as there very close to being past the hose and leave them out. I cant see how they were opening all the way so maybe I get a performance surprise when this baby hits the water again.

Oh, and how do I remove these old depth sounders?


Today its been spitting rain. So I worked on the outdrive, removed the old transom gasket and cleaned out all the old crud. Cleaned all the oil and old grease for the input bellow and cleaned all the old gasket channels. Also, the u-joints look brand new in that they are showing no rust. Should I go ahead and replace them to be on the safe side?

 

[tfitch03]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Awesome progress! Great looking boat.

 

[rickryder]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Nice rig and a great start on the rebuild! Best way to remove all the solid wood is to take your circular saw set the depth 1/4 higher than your transom wood and score it in a bunch of places.... chisel it out and use a 36 grit flapper disc on an angle grinder to remove the remaining wood....Just be sure to set the depth so you don't cut through the outer shell!!

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

HF, I had the same reaction. The staples did make removal easier, but i can't believe they added much strength. For removing the good part of the transom shield, I did just as rickryder suggests: I set my saw depth a bit shallower than the plywood, and then I made crisscross cuts every two inches. These I whacked out with a chisel and a mallet. Not fun. Even less fun was getting the old peanut butter off the transom shell. In some places it was almost a half inch thick! I was grinding on that for days. I don't know if you can tell from this picture, but the section on the right is ground down to the hull; the part around the keyhole is really built up with PB. More than half the thickness around the keyhole was PB and it had to be ground out.





I didn't find any cardboard shell in my stringers. It was very thick fiberglass over foam.

I am planning to make bases for my pedestals. I haven't heard of anyone having problems with that construction (glued down with PB, then glassed in with 1708 and or CSM). It's particularly funny you mentioned building circular pedestal bases... I am considering exactly the same thing! I'm not sure how hard it would be cut 1.5" on a 45 degree angle while following a circular line. I also considered an octagon shape. My biggest hesitation is that I don't know if laying mat or 1708 would be easier over an octagon or circular shape versus a square. I'd be interested in hearing your (or others') thoughts on that. But yeah, I think it would look good.

As for the depth sounder puck, I gave mine a good pop on the side with my mallet and it popped right out.

Good luck getting the old transom out and grinding down to the hull. I found that to be about the least fun part of the project. It was ALL better after that!

Jim

 

[Nivekt]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Good progress. Subscribed.

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Gents, I have a contact at a local automotive hardware store and I was thinking of ordering all my fiberglass from him. Would there be any difference between fiberglass products that are used in the automotive and marine industries?

 

[GT1000000]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

You should definitely do your due diligence and verify that the resin is a laminating/ lay-up type that can be used for marine and that it Does NOT contain any wax in it...
The rest of the materials like 1.5oz. CSM and 1708 Biaxial cloth should be the same...
Rest of the stuff like Cabosil/Aerosil, milled fibers, etc. are what they are...
I would question any substitutions very carefully...
My 2?...

 

[Woodonglass]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I'd suggest you do some MAJOR pricing research. 15 Gallons of Resin from the Auto Supply, IMHO, will be MUCH more expensive than from a major Resin distributor unless he sells it to you at a minimum over costs.

 

[rickryder]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

I have never found auto resin that doesn't contain wax... Go with US Composites for it. 435 Standard Polyester Layup Resin
(Marine Grade Resin) $125 for a 5 gal pail Polyester Resins

 

[tpenfield]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Yes, I agree . . . resin from auto supplies and home improvement stores, etc will most likely contain wax pre-mixed in . . . only good for a single application, not for laminating. The marine oriented supply sources will provide the wax as a separate additive, so you can use it only when you need it as a top coat cure.

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Thanks for the comments on the fiberglass. I will try another contact with Concord Boats. Here are some pictures from today. As suggested, I made cross cuts every 2-3 inches and went to town. That made things go much quicker with the chisel. Then I grabbed the flap disk on the 4 in grinder and went to town.



This morning I went all around town searching for plywood. It pretty much came down to CCA plytanuim which I found to be full of knots and then I actually found AB marine plywood and decided to go with that. Hope I made the right decision...

 

[ezmobee]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Can't go wrong with marine ply.

 

[JASinIL2006]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Looking good, man! Don't you love grinding fiberglass?

You're making great progress.

Jim

 

[HalfFish5087]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Thanks Jim, even though I was wearing the tyvex suit, it worked its way onto my ankles, face and arms. Yes, grinding glass is awesome and I really can't wait till I'm done.

Hey do you ever make it on any Missouri Lakes; Clearwater, Table Rock, Lake of the Ozarks?

 

[rickryder]

Re: Is it worth it? '98 Larson 5.7GS DP Lower Transom Rot

Use lots of talc powder before you suit up on the places your getting glass infiltration.... helps alot !