Foam vs. No foam

BuffaloBFN wrote: I'd luv to see the lam schedule for an 88 BFN. How does one get that info? And don't say 'Ancient Chinese secret'.

MIskier wrote: That is not something that you will be able to get a hold of, but if you pull out a thru-hull fitting you can see your hull thickness.

What's the big problem with getting the layup? Maybe with a MC since they don't want people to know just how thin their hulls are???!!

Greg, all that's needed is to call Dave.

BTW, pulling a thru-hull to see the lay up isn't the greatest idea. Decent boat builders will build up the area with a couple more layers of glass.

Riley wrote: Pete, the MC salesman at the Boston show showed me a cut out from the bottom of a hull and it was about 3/4" or maybe even an inch thick.     Course, as you note, maybe they build them up around their through hulls and that's not a good representation of how thick their hulls are, although that's the claim he was making.

Ha, it sounds like that salesman was... a salesman.

Ive dissected a few CC's and the hull thickness can approach 1/2" or more in a few places- namely the keel, or around certain through hull hardware. Most areas of the hull are much thinner- between 1/8" and 1/4", generally speaking.

On a 20+ year old boat?! I highly doubt that got saved during the move.

Haha very funny you're all so original with your MC bashing.

Bashing is part of competition. The salesman I refer to was actualy a sales rep from Mastercraft and our conversation started out with him telling me how Malibu and Nautique were poor quality boats compared to a Mastercraft, he was bashing. When I told him I owned a fairly new Malibu, he backed off, but I told him he wasn't hurting my feelings and I wanted him to show me why he thought his boats were better. He went on for a half hour. I was impressed with the thick plug he showed me and I asked him if maybe due to all that weight from the thickness of the hull was the reason why the Pro Stars are so slow out of the hole and at top end. He actually told me they were designed to be slow as ski boats don't need to be fast. Tim, I think that was the Sunday after the Saturday that you guys were eating Cheezits in his boats.

Anyone ever try putting a match to a pool noodle?

Agreed, thicken your skin that was just good old fashioned salesman bashing!

The layup in the non foamed areas of my 83 was thicker than in the originally foamed areas

This likely had more to do with the proximity to keel, larger span between stringers, relative flatness of the area in question, etc. than the simple fact that the area wasn’t foamed but nonetheless the bilge where I cut through for the paddle wheel was 3x thicker than the area forward between the stringers that I cut through due to carelessness.

I dont disagree that the layup on a skiboat is in general considerably more substancial than is required by the loading seen on the hull during normal use.. however I tend to not discount the abnoral situations very quickly. I am not sure that I wouldnt possibly see a rock, log, or worse at some point (hopefully not at speed but it can't be ruled out).   Even a broken or poorly designed trailer or hoist bunk can provide significantly larger point loading than a boat sees in normal use.

My position remains that you dont need no rottin, stinkin foam.. but if you simply remove it and dont give any thought to replaceing the benefits it supplies you may (although likely not on most of these boats) someday regret it..

JoeinNY wrote: Agreed, thicken your skin that was just good old fashioned salesman bashing! The layup in the non foamed areas of my 83 was thicker than in the originally foamed areas This likely had more to do with the proximity to keel, larger span between stringers, relative flatness of the area in question, etc. than the simple fact that the area wasn’t foamed but nonetheless the bilge where I cut through for the paddle wheel was 3x thicker than the area forward between the stringers that I cut through due to carelessness. I dont disagree that the layup on a skiboat is in general considerably more substancial than is required by the loading seen on the hull during normal use.. however I tend to not discount the abnoral situations very quickly. I am not sure that I wouldnt possibly see a rock, log, or worse at some point (hopefully not at speed but it can't be ruled out).   Even a broken or poorly designed trailer or hoist bunk can provide significantly larger point loading than a boat sees in normal use. My position remains that you dont need no rottin, stinkin foam.. but if you simply remove it and dont give any thought to replaceing the benefits it supplies you may (although likely not on most of these boats) someday regret it..

3X thicker at the keel Every boat that I have dealt with as far as the lamination is concerned has never varied that much in such a short span. Generally it has varied by several layers, never multiples of the hull thickness.

Mike,
Don't worry about hating yourself for commenting as this subject has come up many times with many opinions and yes "seat of the pants" engineering!!

I feel the era (year) of the boat hull makes a big difference. Early glass hulls were thicker and certainly did not need the foam. Then, as years past, hulls were made thinner and the added rigidity of the foam was "engineered" into the hull strength.

One thing to keep in mind is old wet foam does not provide any support and to this day, I've never seen a hull fail do to the lack of the added strength of foam.

8122pbrainard wrote: One thing to keep in mind is old wet foam does not provide any support and to this day, I've never seen a hull fail do to the lack of the added strength of foam.

I gotta disagree with you here, Pete. Soaked or not, foam does lend structural rigidity between the hull and floor. You and I both know that there are many boats running around with rotten stringers, yet somehow they still hold together. Im not sure that would be the case if the only thing holding the boat together were rotten stringers (no foam to keep everything moving together).

I dont know about you, but I dont know of any boats that have had their foam removed, then sealed back up with rotten stringers. That seems like a recipe for disaster. A foamless boat (whether the stringers are old or new) is not likely to fail, as the stringers are not likely to be rotten in the first place... so thats not what Im referring to.

Like you, Im a no-foam guy because I hate holding water in the structure. I like the fact that foamless structures can drain and breathe- so they should be much less prone to rot. What Im saying above is that if rotten stringers are a foregone conclusion, Id much rather have foam down there holding everything together rather than rotten stringers alone.

TRBenj wrote: 8122pbrainard wrote: One thing to keep in mind is old wet foam does not provide any support and to this day, I've never seen a hull fail do to the lack of the added strength of foam. I gotta disagree with you here, Pete. Soaked or not, foam does lend structural rigidity between the hull and floor. You and I both know that there are many boats running around with rotten stringers, yet somehow they still hold together. Im not sure that would be the case if the only thing holding the boat together were rotten stringers (no foam to keep everything moving together). I dont know about you, but I dont know of any boats that have had their foam removed, then sealed back up with rotten stringers. That seems like a recipe for disaster. A foamless boat (whether the stringers are old or new) is not likely to fail, as the stringers are not likely to be rotten in the first place... so thats not what Im referring to. Like you, Im a no-foam guy because I hate holding water in the structure. I like the fact that foamless structures can drain and breathe- so they should be much less prone to rot. What Im saying above is that if rotten stringers are a foregone conclusion, Id much rather have foam down there holding everything together rather than rotten stringers alone.

Tim,
There are times that you are as ADD as I am!! Please note that in my post, I never mentioned stringer issues. It was simply hull thickness and foam adding to the rigidity of the hull!!

What keeps the boat in shape is the floor/stringer/hull combo, I dont know why foam is being thrown in the structural discussion.

if you had to build a boat
Would you cheap on the floors?
Would you cheap on the stringers?
would you cheap on the hull?
would you foam or not foam? This is the only debatable issue, because i'ts not fundamental to boat building structure.

And hulls are ticker on the keel because that's where all the unattached resin ends while laminating!!!

Hulls dont need to be rigid, just on certain points, too rigid cracks, some flex points are even good for the structure.
And I suggest checking on the newer CCs before talking on other brands lamination, as they have gotten thinner lately.

Greg, my point is from a structural standpoint, the foams add little or nothing, you could fill it with concrete, but it's still unneeded.
How many boats are running no foam and no catastrophic failure occurrs?

As Miskier stated these boats are way overdone on structure, specially the old ones, the stringer we are used too see are unthinkable on most other boats.

Yes, there's the CG regs and the sound dampening, but that's a whole different matter. probably a composite hull without any foam would sound very shallow on the chop.

Anyone ever think of using 2 litre soda bottles? They would last forever, provide flotation, and not hold water if capped. They offer no structural support but noodles can't be much better.

As for the bashing. If it comes from a salesman, it might as well come out of a politition. The crap the reps feed you about how good your product is versus how bad the other guys stuff is usually about 99% bull.

I have an 80hp Mercury with the blue stripe on my dad's 1978 16' boat. Awesome motor.

KRoundy wrote: Gary, I LOVE that old Merc. Nice shot!

Unfortunately Kevin that old '64 is history.Last winter it started to have starting issues.You have to pull the powerhead to remove the starter.Dad being in his mid 80's just can't work on them anymore or use the pullstart if need be so he took it in and was advised that it was not worth it.That and the fact it was in Florida saltwater now,the wiring was going too.Before I could get it back he had got rid of it.So this spring he found a low hour '03 Mercury 25 up here and he's going to ship it down.

I restored a Glastron Skiflite a few years back (I still don't know why) . The hull was in nice shape, but the floor and stringers were mud. The PO had screwed a sheet of treated 3/4" plywood to the rotten floor with drywall screws that were a little too long. When I removed all the material from this quality repair I found that he had stuffed pool noodles under the floor through some holes he made before he screwed the plywood on top of the rotten floor. The pool noodles were saturated and almost as heavy as concrete. They broke apart under their own weight when handling them. I left a big piece of one out all summer to see what would happen. It only lost a little weight.