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!987 Chaparral 235 XLC Plywood Cored Hull Issues

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Hi New to the forum, but have owned two Chaparral boats a 1991  2370 sl and at present restoring an older 1987 235 xlc.

 

After approx 6 months of complete restoration including new transom, bulk heads and complete stringers, I have just discovered that the complete center of the bottom hull from the cuddy door to the transom and under both engine mounts is cored in plywood,

Before beginning this restoration i researched all the information on this boat and all chaparral literature stated that these boats were solid fiberglass hulls,

As can be seen below, this was under the fuel tank, wet plywood coring in the bilge area that is always full of water, and in the engine compartment under both engine stringers.

Not sure if anyone has any idea on going about repairing this,

but after 6 months of hard work and sweat, i am really frustrated and disappointed that none of Chaparrals literature mentions any wood coring below the waterline.

I have repaired many boats including a complete bottom peel and relaminated a 45 foot lancer powersailer,

But this one really has me stumped. as the laminate underneath the wood core is only approx 1/8 of an inch or less including the gelcoat, it seems that this may be a lost cause in attempting any further repair.

 

This really sucks..

 

Thank you

 

.

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What you're dealing with is essentially the keel of the hull. The wood actually doesn't look too bad. If you treated it with ethylene glycol to kill the rot, let it dry out, and then reglassed, you may be able to keep it as is. Good luck!

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Thank You for the reply.

 

Unfortunately the plywood on the sides of the bilge, a large area that supports the fuel tank although not rotten is delaminated from the outer layer of the hull in many areas, 

The core is also delaminated under both Engine mounts, The glycol would have worked if the was no delamination, 

 

But under the Engine  mounts with over 1000 lbs of weight any delamination or wet plywood core would definetely not be safe.

 

On the second picture it shows the tank area with the wet plywood removed, from there you can see the keel and how large of an area is affected.

 

Thank You 

Lui

 

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Sounds like you have a good grip on the situation...I would cut out and then glass new wood in. That wood is the keel and not part of the actual hull laminate.

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To prevent twisting the hull out of shape.Do SMALL sections. Stop exploring too much area. Do center line checks from a distance. Do side checks for sags or humps. You have a real baddy. Forget the useless anger. Continue with repairs & sell it.  Or strip it for parts.  Block up low areas if they appear.

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1 hour ago, cyclops2 said:

To prevent twisting the hull out of shape.Do SMALL sections. Stop exploring too much area. Do center line checks from a distance. Do side checks for sags or humps. You have a real baddy. Forget the useless anger. Continue with repairs & sell it.  Or strip it for parts.  Block up low areas if they appear.

 

Thank You for the reply, and I agree about the hull shape, fortunately the stringers bulkhead and transom are all finished, new wood was installed with 1708 and Epoxy and is reinforcing the hull along with proper blocking along the centerline from below,

Unfortunately the wet plywood was discovered after the other repairs were complete, The issue is definitely part of the bottom hull layup and not the keel as stated in another post.

I have seen and repaired Keels on Sailboats, Fishing Trawlers and other Off Shore displacement hulls, but definitely have never seen a Keel on a Chaparral.

Placing plywood coring low in the bilge area of a boat hull that is constantly holding water was definitely a bad idea.

I posted here hoping someone had gone through a similar situation and how they went about the repair.

And parting the boat is still on my mind, Just trying to find a solution before throwing away all the work I have done.

 

Thank you

 

Lui

 

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Seems like a ton of work and money. Is this boat worth all this time and money? Seems you could get this old of a boat without the problems for pretty cheap. Maybe sell off some parts like motor outdrive windows ect and just by another. Unless there is some attachment too it then I totally understand and have at it. Love to see pics of the process.

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Lots of parts on that boat that go for some $$$. Cut the back of the boat out and sell to someone to make a bar out of it. Actually have a buddy who did that at his lake cabin. It's pretty cool.

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15 minutes ago, 2004lebanshee said:

Lots of parts on that boat that go for some $$$. Cut the back of the boat out and sell to someone to make a bar out of it. Actually have a buddy who did that at his lake cabin. It's pretty cool.

Lol, hoping to have made it into a floating bar,

Unfortunately it seems that I have maxed out my pic allocation on this post.

 

Lui

 

 

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7 minutes ago, tosea said:

Lol, hoping to have made it into a floating bar,

Unfortunately it seems that I have maxed out my pic allocation on this post.

 

Lui

You need to post the pics on a pic site and transfer the links.

 

 

 

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What you are looking at is in fact the keel stringer. It reinforces the keel of a planing hull power boat and ensures that the hull does not flex and warp. Although different than a displacement hull keel, it is indeed a sort of internal keel if that makes sense. I full understand that it's not a real keel like you'd see on a sailboat or trawler...

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Hi , Not trying to bring back the old post as that boat has been put to rest,

 

I am now looking at a 1992 signature 260, But would like to know what year chaparral stopped using plywood as coring in their hull bottoms.

Do not want to go through another nightmare.

It is very unfortunate that no literature exists that specifies that plywood or plywood squares was installed as coring along the centreline of the hull below the waterline.

All the literature and any post I have ever read states solid glass is used below the waterline.

 

 

Thank you

 

Lui

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5 hours ago, tosea said:

Hi , Not trying to bring back the old post as that boat has been put to rest,

 

I am now looking at a 1992 signature 260, But would like to know what year chaparral stopped using plywood as coring in their hull bottoms.

Do not want to go through another nightmare.

It is very unfortunate that no literature exists that specifies that plywood or plywood squares was installed as coring along the centreline of the hull below the waterline.

All the literature and any post I have ever read states solid glass is used below the waterline.

 

 

Thank you

 

Lui

It's too bad you went through all that work on the 87 235xlc only to end up putting it to rest, shame.  Don't mean add salt to the wound, just genuinely feeling for you since I've been through similar experiences like that (not on boats but in other fields) and know what it's like.  Definitely not fun and not just the time wasted, but in this case, money, too.  I'm curious what you meant by "put it to rest"? :)

As far as your other question about when Chaparral stopped using plywood coring.  I'm not sure but I don't think they necessarily stopped using it, but rather switched at some point to a balsa core if I'm not mistaken.  I know that some of the early and mid 90's boats had switched to the balsa core infused with the fiberglass.  Then at some point after that, they went to straight FB and even went with Kevlar enforced FG hulls which is what mine is.  Stringers are pressure treated lumber and bulkheads are marine plywood all glassed in.  So my best guess on the 1992 Signature coring will probably be balsa, at least on the sides of the hull.  Bottom might've still been plywood simply because I would think it needs to be stronger.  Hard to tell like you said unless you drill a hole.

It's too bad, though, on the 235.  How much thickness was there left on the fiberglass bottom past those plywood squares?  Could you have removed as much of the rotted stuff and filled the voids with 1708 and resin, or even epoxy?  There are quite a few other filler materials available too.

 

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Hi, putting the boat to rest,  well decided to completely part her out to bare hull, and took the hull to a recycling facility, did real well on selling the parts, more the recouped my money but lost out on the labour,

 

Really sad to see it go, but did not feel safe doing that repair after all the new stringers bulkheads and transom were in place,

It would have required removal of the new stringers in order to get continuous  layers of glass layed down properly to reinforce the hull prior to re coring.

At one point I estimated the thickness between the plywood core bottom and gelcoat was 1/8 th of an inch,

But before disposing of the boat I took a few measurements with a micrometer and the actual thickness was 2/16, there was only the gelcoat and some really dry chopper gun chopped strands before the plywood coring. No roving at all,

Really weak layup, would have hoped to have seen at least 1 layer of roving prior to the coring.

In the photo below you can actually see the hole next to the chisel  which is directly under one of engine beds .

Strange thing is I have always love the styling of chaparral boats and keep looking for another one,

But this plywood coring issue below the waterline really makes me think twice.

 

Lui

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Drew could likely provide some insight here . . . former member . . . prolly still reachable . . . Hatem, you still in touch with him?

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3 hours ago, Futzin' said:

Drew could likely provide some insight here . . . former member . . . prolly still reachable . . . Hatem, you still in touch with him?

I do.  Just talked to him a few weeks ago.  Were planning on hooking up in Miami and riding the 276 with Jeff's 310 to Islamorada for a few days, but Michael decided to come up the west coast and dump a bunch of rain and wind and basically ruined the trip for us.  Plus there was a nasty case of red tide on top of all that, definitely put a damper on the whole plan lol.

We had a great thread going a few years ago on the use of wood in boats and specifically Chaparral.  A lot of great info and pics and perspectives.  But this was back when participation was much better around here.

3 hours ago, tosea said:

Hi, putting the boat to rest,  well decided to completely part her out to bare hull, and took the hull to a recycling facility, did real well on selling the parts, more the recouped my money but lost out on the labour, 

Well that's the best case scenario, then.  It's a labor of love, anyway, so no worries since you get compensated or that part in many other ways.

3 hours ago, tosea said:

Really sad to see it go, but did not feel safe doing that repair after all the new stringers bulkheads and transom were in place,

It would have required removal of the new stringers in order to get continuous  layers of glass layed down properly to reinforce the hull prior to re coring.

So how did you find out that plywood bottom was delaminating?  Were the new stringers you put in sitting nicely and you were able to tab them and glass them anyway?  At some point you must've noticed the plywood giving up and separating.  Too bad you didn't check that first.  I do agree, though, that delamination is a completely different story than actual rotting.  Rotted sections can be removes and filled in, but delamination is much worst since that basically means all the plywood is failing completely, and usually it wouldn't be just in one section.  It would be the entire surface or almost the entire surface area or plywood.  The issue is the glue they used to laminate the layers of plywood back in the day just wasn't good enough to hold up to the moisture.  I see it all the time in my business (construction) in older plywoods.  Delamination is actually not that uncommon.  Add it to a moist environment like boats and it's twice as bad.  The old plywoods were just not as good as today's, marine rated stuff.  The new stuff is made with much better and long-lasting adhesive and pressed in the right temperatures and curing time.  Even regular plywood will rot first before delaminating.

3 hours ago, tosea said:

But before disposing of the boat I took a few measurements with a micrometer and the actual thickness was 2/16, there was only the gelcoat and some really dry chopper gun chopped strands before the plywood coring. No roving at all,

Really weak layup, would have hoped to have seen at least 1 layer of roving prior to the coring.

In the photo below you can actually see the hole next to the chisel  which is directly under one of engine beds .

Wow.  To think that the actual FG layer is only 1/8th of an inch is shocking at first, but when you think about the eventual thickness that they were after WITH the appropriate plywood coring, it's actually good.  I'm guessing that plywood was around 3/4"?  Add that to the 1/8 FG and any additional glassing layers and you're around 1" of thickness, which isn't shabby at all.  Only problem is that plywood is junk.

BTW, you'll see some of that dry, chopped strand occasionally even in today's boats.  There was a fella from the UK who bought a 2017 Sunnesta Surf and had major issues with it and from the pics he posted of the bilge you can see that dry chopped strand all over the place with just gelcoat brushed on it.  It's almost like they mixed a peanut butter tabbing mix and didn't add any silica to thicken it and barely enough resin to stick together and just threw in a bunch of dry strands to build it up that way and just painted over it.  It was really awful.  I think that particular boat was an exception. 

3 hours ago, tosea said:

Strange thing is I have always love the styling of chaparral boats and keep looking for another one,

But this plywood coring issue below the waterline really makes me think twice.

Well, here you go.  Like I thought, it's basically a balsa core with marine-grade plywood for stringers and bulkheads and floor base with several layers of woven roven and fiberglass matting in the 1994 Chaparrals.  The hard part is whether they made the shift to this balsa core prior to or in 1994.

http://forum.chaparralboats.com/publications/brochures/1994/1994.pdf

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6 hours ago, Dennis A said:

Hmm...?  

Hummm, too funny, that must have been the guy I bought the boat from, Same picture that was in the listing on a local classified site.

I did buy the boat from him in August or Sept of 2015,  will have to look at the bill of sale for the exact date.

He told me it needed a starter, but forgot to tell me about the Connecting Rod that went through the block after he hydro locked the motor.

Good find guys

Lui

 

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8 hours ago, Denny said:

I think sst's is an 85, just like mine. I believe the 85 and 87 are the same boat, they just changed the ginger bread design.  Denny.

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Denny I looked at your thread many times while rebuilding mine, found the same issue with the leaking fuel inlet hose under the floor on the starboard side.

Major difference was your floors the floatation foam and stringers were all dry, Someone took great care of that boat, as it should be.

 

Lui

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I can't believe I missed this post when originally posted. Maybe its for a good reason as I'm running out of nails to bite. haha. Is she gonna split?!

My boat is an 87.

I've done a lot of wood repair/replacement. All above the floor. The closest I got to going underneath was the installment of the new gas tank filler tube. Too chicken to rip up the entire floor and tank.

This post has me a little uptight. The previous owner to my brother must not have been paying attention to how much water was getting in. Some of the wood was so extremely rotted it was actually powder and it was the vinyl itself holding everything together. Over the years, I've pretty much have "plugged all the holes" where water enters. The biggest entry was the engine compartment air vents. You might as well use a bucket of water with a funnel. I ended up cutting some black pool cover plastic with Gorilla tape and covered the vents. They work very well and the engine compartment stays dry even in the hardest rain.

But even with no water getting now, this has me worried about what damage lies beneath from the original owners lack of care.  

 

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5 hours ago, tosea said:

Denny I looked at your thread many times while rebuilding mine, found the same issue with the leaking fuel inlet hose under the floor on the starboard side.

Major difference was your floors the floatation foam and stringers were all dry, Someone took great care of that boat, as it should be.

 

Lui

I'm still curious as to the stringers and bulkheads you put in before discovering the delaminating plywood.  I don't see any new stringers in the pics you posted.  It looks like you're pulling up almost all the bottom hull plywood and no stringers in site.  I see the new transom, but am I missing something?

EDIT:  Never mind, I see them now in the top pic.  It didn't show up on my phone for some reason.  Yeah, that definitely wouldn't have made sense at that point.  Even if you hadn't put in any of the stringers and bulkheads, removing all that plywood and ending up with a 1/8" bottom to work with and strengthen would've been really tricky.  The whole hull would be very flimsy and could twist without sitting in a mold of some sorts.  Would've been very difficult to repair correctly.  You did the right thing.

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