Delamination??

nitedmn

nitedmn

Petty Officer 3rd Class
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Jul 3, 2005
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My dad recently gave me his old 1972 Marlin Leo which he originally bought brand new (I grew up riding around in the boat). He's always taken pretty good care of it but it was sitting for 10+ years before he gave it to me. I've had it out on the water a few times and each time I've run into a minor mechanical issues (first trip was a clogged up carb and the next two were shifting problems) and I'm currently waiting for a new shift cable. While removing the old shift cable I noticed some cracks in the floor of the engine compartment. I pulled a little on the edge of the crack and a piece of resin/fiberglass snapped off. I also noticed a crack running down the side of each of the stringers the motor is mounted to.

Here are some pictures of the issue
https://goo.gl/photos/VHnK6dyxQdNaHBSp7

The boat was always stored inside and has never had any problems with rot or moisture anywhere. Around 15 years ago the floor was replaced after the gas tank rusted out and leaked a full tank of gas over everything (gas tank is in the bow). The floor under the carpet shows no issues and I don't know if they replaced it all they way to the transom (I'm guessing they did not). I've never worked with fiberglass but, after doing several hours of research, it doesn't look horribly difficult.

What is the best way to repair this?

I am going to need to pull the engine out to repair the stringers?

If I pay a shop to do this, what kind of cost can I expect. I'm not looking for an exact price, just a rough estimate. Are we talking a few hundred or a few thousand?

Thanks
 
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Scott Danforth

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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yes, if the stringers are bad, motor needs to come out

if you take it to a shop to repair, estimate about $5k - $8k for stringers, floor and transom

if you do it yourself, estimate up to $3k in materials and about 200 hours for labor.
 
tpenfield

tpenfield

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The pictures show some issues with the structure but it is difficult to tell exactly from just pictures. A re-build would be a few thousand $,$$$.
 
nitedmn

nitedmn

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The stringers themselves, and all the wood, look fine. It's the the glass peeling off the wood which seems to be a problem. I'm guessing I could just grind off the lose pieces and re-glass the floor (it's a pretty small section) but I'm not sure about the cracked glass on the stringers. Is there an easy way to repair that (assuming the wood is still good) without having pull the motor and grind everything down?

I've got a lot of memories with this boat so I'm willing to put in the time and money needed to keep it going but I currently have a pretty limited budget.
 
Woodonglass

Woodonglass

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IMHO the only way to know for sure if the wood core in the stringers and transom are actually good is to drill them and check the shavings. If the boat has been covered in the off season and never had any exposure on the topside with water etc.. then they could be OK. Drill them to make sure. If the wood core IS good all you would have to do is sand them down, wipe with acetone put a heavy coat of resin on them, let it tack up and then another coat of resin and one layer of 1708 fabric and they would be good to go. this is assuming that the tabbed attachment to the hull is still good.
 
Ned L

Ned L

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I'm going to go and "assume' the wood is solid for the time being. ....... For a minute, let's talk about what I see in the pictures and how I think your boat is built. It looks like the bottom has a layer of plywood inside the bottom (between the stringers), is this correct? this is not unusual for flat bottom boats, and yours looks like it is almost flat bottomed. When the boat is built they lay up the glass hull in the mold, cut and fit in sheets of plywood that cover the flat areas of the bottom, glue & glass those in place, then set in and glass in the stringers.
I'm going to guess that when the bottom was repaired from the leaked gas that the 'fiberglass' (fiberglass cloth and polyester resin) was stripped away from the topside of the plywood and partly up the stringers. (The plywood may or may not have been removed and replaced), and then new polyester resin was applied on top of the plywood and up the sides of the stringers.
It appears that the resin on top of the plywood has no fiberglass cloth in it and is only resin. Polyester resin is only the "glue" and does not have much strength on its own (it also becomes very brittle over time).
If all this 'guessing' is correct, what needs to be done is to pull the engine, remove the old brittle resin, and if the wood is all solid, fiberglass the inside properly with glass cloth (others here can better comment on the type of cloth to use), and I would use epoxy resin instead of polyester resin (epoxy bonds much better to old material and wood that is less than perfectly clean.
Again, a good bit of this is based on guessing on the pictures and what you have said so far. More information from you would be very helpful.

IF the wood is in fact all solid, I'm seeing not more than a couple of hundred for the materials (and you do all the work).
 
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nitedmn

nitedmn

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Ned L said:
It appears that the resin on top of the plywood has no fiberglass cloth in it and is only resin. Polyester resin is only the "glue" and does not have much strength on its own (it also becomes very brittle over time).
Click to expand...

This does appear to be correct. The piece I broke off (seen in the first picture) did appear to be only resin with no glass in it.

Ned L said:
If all this 'guessing' is correct, what needs to be done is to pull the engine, remove the old brittle resin, and if the wood is all solid, fiberglass the inside properly with glass cloth (others here can better comment on the type of cloth to use), and I would use epoxy resin instead of polyester resin (epoxy bonds much better to old material and wood that is less than perfectly clean.
Again, a good bit of this is based on guessing on the pictures and what you have said so far. More information from you would be very helpful.

IF the wood is in fact all solid, I'm seeing not more than a couple of hundred for the materials (and you do all the work).
Click to expand...

This is was I was hoping someone would tell me and what I believed to be true. I just don't have any experience with this material and wanted to be sure.

Woodonglass said:
IMHO the only way to know for sure if the wood core in the stringers and transom are actually good is to drill them and check the shavings. If the boat has been covered in the off season and never had any exposure on the topside with water etc.. then they could be OK. Drill them to make sure. If the wood core IS good all you would have to do is sand them down, wipe with acetone put a heavy coat of resin on them, let it tack up and then another coat of resin and one layer of 1708 fabric and they would be good to go. this is assuming that the tabbed attachment to the hull is still good.
Click to expand...

Similar to what Ned said and what I hoped would be the case. I will certainly check all the wood carefully before covering it back up again. The small section of plywood that is currently exposed looks like it just came off the shelf in the store. My belief is that everything else is in similar condition.

Thanks everyone for the advice. Now I guess I need to find out if the ceiling in my garage is high enough to allow me to lift the motor out.

Here's a little more history on the boat in case it changes your opinion any...

Purchased new in 1972 and used frequently for about 15 years (I was born in 1976). In the late 80's it was left outside, covered in tarps, for a period of time. These tarps trapped a bit of moisture in the engine compartment and caused the engine to seize (I remember watching a 350+ pound person stand on a breaker bar. He manged to get the engine to turn about 1/8 of an inch). At this time my dad had the entire engine and lower unit rebuilt. All this work was done by a good friend who spent his life working on boats and really knows what he's doing. He would have checked for any rot before installing the new motor and probably wouldn't have allowed my dad to put the motor back in if there were any problems.

At the end of the rebuild the leaky gas tank was discovered. Instead of replacing the tank, my dad opted to have the existing tank cleaned and lined with something to seal it (not sure the exact process they used). Around this time the upholstery was also redone since the original vinyl was starting to fall apart.

Apparently the gas tank sealing process didn't work that great since it was a few years later when the big gas leak occurred. This leak ate away all the foam that was under the floor and caused some soft spots. The floor, and gas tank, were then replaced. For the next few years the boat was used once or twice a year and remained in the garage the rest of the time. Then it sat, in the garage, for another 10+ years without being used at all. At that point my dad decided to give the boat to me hoping I could get some enjoyment out of it. So far I have more hours working on it than hours on the water but it's still been enjoyable.
 
mickyryan

mickyryan

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wonder if they are bad or if they just cracked from moisture and since they cracked and its been kept in storage they dried out , you might get lucky and just need to reseal them .
 
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