TOPIC: 1972 Lund (Shell Lake) Trihull questions

I'm not sure whether this is better posted here on in the "Disco" forum.

I posted earlier on this and bought the boat in spite of some warnings. ( www.fiberglassics.com/glassic-forums/main-forum/lund-trihull-any-good )

Model TH-15 I-O Serial 3044

So far, the hull seems quite sound to me except for the floor which is soft in places and will have to be cut out and replaced. But I was told this is a "balsa cored hull" and am wondering how much balsa core there is and where. Can anybody advise?

Are there pics/literature on these boats posted anywhere, or is Lund likely to have anything?

As predicted, parts for the Renault-powered outdrive require some scrounging.

I notice the rear deck/engine cover are about a foot longer than needed for this power plant. Basically wasted space. Looks as if they left room for a largr engine? Anybody know what was available?

The bow area has what look like snaps to hold cushions in place. But about two inches below the gunwhale there are two rows of holes and below that some rust stains. Anybody know what the setup was?

Thanks in advance ...

am

amuller wrote:

I'm not sure whether this is better posted here on in the "Disco" forum.

I posted earlier on this and bought the boat in spite of some warnings. ( www.fiberglassics.com/glassic-forums/main-forum/lund-trihull-any-good )

Model TH-15 I-O Serial 3044

So far, the hull seems quite sound to me except for the floor which is soft in places and will have to be cut out and replaced. But I was told this is a "balsa cored hull" and am wondering how much balsa core there is and where. Can anybody advise? The hull is a chopper gun layup that incorperates a balsa core in the laminate. Essentially, the hull has a laminate sprayed into the mold, then a layer of 1/2 balsa layed "end grain", then another layer of sprayed laminate to complete the hull bottom. The balsa will be in the bottom only, from transon forward and chine to chine. The hull sides will be a solid laminate. After the sandwich is completed, the stringers are glassed in then the floor goes down. If water gets into the sandwich, it stays and creates saturated areas which typically delaminate, rot and become soft. Strength is compromised.

Are there pics/literature on these boats posted anywhere, or is Lund likely to have anything? I doubt Lund has any info.

As predicted, parts for the Renault-powered outdrive require some scrounging.

I notice the rear deck/engine cover are about a foot longer than needed for this power plant. Basically wasted space. Looks as if they left room for a largr engine? Anybody know what was available? In later years, Lund built 15' boats and offered 120/140 power. I would assume they were continuation of boats originally built for the Renaults

The bow area has what look like snaps to hold cushions in place. But about two inches below the gunwhale there are two rows of holes and below that some rust stains. Anybody know what the setup was?

Thanks in advance ...

am

Thanks very much for the info. I'm clearer now about why boats made this way don't seem to be considered good candidates for repair/restoration.

On the good side, the bottom seems solid as much as I can tell from tapping on the outside.

Is there a reasonable way to repair this hull?

Thanks again.

am

Thanks very much for the info. I'm clearer now about why boats made this way don't seem to be considered good candidates for repair/restoration.

On the good side, the bottom seems solid as much as I can tell from tapping on the outside.

Is there a reasonable way to repair this hull?

Thanks again.

am

They are still repairable, just one more step along the way.

In my opinion, a 1972 trihull won't be on the top of the collectable list. That being said, I personally have 5 I/Os, 3 are OMC drives and 2 MerCruisers (no Renaults), all useable.

So, most people have nothing but bad to say about the OMC stringer drives. I however like them. Most people hate trihulls, I have 2.

If you like the boat, go for it.

Jim

Jim:

Thanks for the input. I know this is not a particularly collectible boat. I want it for exploring around on the water--we live in a Mississippi River town--and I think a trihull is practical if not beautiful. Not sure I'd want one for coastal use....

As for the Renault, people don't seem to have
anything good to say about them, but I'm not hearing many specifics about problem areas. The cooling system plumbing seems a bit goofy, and parts aren't easy to come by. There seems to be no reasonable way to set the timing. But what is actually unsound about it mechanically?
No doubt that in this power range an outboard is more practical, but on the other hand this won't belch oil and smoke like an old OB would.

We shall see how it goes.

Alan

As the owner of 2 Shell Lake I/Os I am happy to see someone hoping to save another. I find the I/Os more desireable because of their rareness.

As for your boat, it was introduced as a 1970 model with 90, 120 & 140 power options.

I am not 100% positive, but I do believe it was designed by Cy Atkinson. Cy was responsible for getting Shell Lake into fiberglass, he left in 1965 to go to Cruisers, Inc. and returned to Shell Lake in 68 or 69 after Lund bought them. 1970 was also the 1st year the conventional "shoe box" type deck/hull joint was used at Shell Lake.

1968 brochures call out the new "TH" series of tri hull designs. So, "TH" in your serial number obviuosly means tri hull. The 15 refers to the size. 3044 is obviuosly a production number, but I don't believe they ever produced anywhere near 3000 boats per year. I would guess maybe your TH was the 3044th built since 1968. That would include all the lengths combined.

As for the Renault I/Os; The original MerCruisers were the GM 4 & 6 cylinder units based on the #1 drive. The #1 drive eventually evolved into the Alpha drive. When MerCruiser introduced the 60 HP (1st Renault), I believe it was in 65, they used a smaller drive called the model 0 drive. The 60 was eventually replaced by an 80 and then a 90 HP engine. The original 60 did NOT have power tilt. It came with a big speed handle and you cranked the drive up. Later drives had power tilt & eventually power trim. That drive was based on an outboard lower unit, but not much it interchangeable. The Renaults used a hydraulic shift slave cylinder (which I have never physically worked on and so am only vaugely familiar with). So, you have engine parts that are rare & drive parts that are rare. The 120 GM quickly became the entry level engine at both MerCruiser & OMC and the Renaults & the oddball small Ford that OMC used were discontinued.

Interestingly, the largest engine hooked to the #1 drive was the inline 250 CID 6 cylinder rated at 165 HP until the 188 302 came out in 1971. Parts are hard to find for pre 1967 #1 drives and especially 1962 & 1963 units. There was a 200 HP 292 CID inline 6 and some V-8s hooked to a #2 drive back in the 60's. The #2 drive would be somewhat similar to a Bravo 2 now. There was also a #3 drive & it was gigantic. Parts are hard to find for #2 & #3 drives too.

Because your boat was available with a 120/140 option, there is some hope of a "plug & play" engine swap. BUT, the transom cutout is different and the GM engines use a front motor mount - yours does not. So, a 120/140 should fit after the transom & bilge is reworked.

If the 90 runs and you use it, I would exercise caution in unfamiliar waters and treat it gentily for longer life span.

Jim

Stray electrons double posted my response & lost my pictures, so I'm putting the pictures here. The green boat is 1971 and it has a 90 HP. The B&W is a 1970.

Yes, that's "my" boat. It doesn't look, somehow, quite as ugly in real life as the picture--square and green, about as un-nautical as can be imagined.

There is plenty of room under the deck for a power plant about a foot longer than the Renault, 90. I haven't measured but it looks as if an inline six could fit (!).

In any case, I've been through the external bits of the drive and fixed everything--it starts, runs, shifts, pumps water (hoses were full of sand! Is this common?), goes up and down... Compression is decent. I'm going to try it out.
One question: Are the current props with removable hubs any more protective of the lower unit gears?

Alan

The hub kit props will be OK to use. BUT, and this but will apply to rubber hubbed props too, Mercury changed hub designs about 25 years ago on the props and that required different thrust hubs to be used. Be certain you have the right combination of hubs & props so everything fits properly. The wrong combination of parts can allow the locking mechanism to not engage & you will find yourself propless. Back in the day (during the transition time) I saw more that one prop installed incorrectly without any thrust hub and then there was gearcase damage.

An inline 6 requires about 41 inches of room. It is another 9 inches longer than the GM 4 cylinder and 700 lbs. I wouldn't try it.

Jim

Oh, I know an inline six would be much too heavy (!) Could locate a Chevy 4 setup but don't know that the boat excites me enough to go to the trouble. Some of the Mercury engineering seems a little odd to me: Not a single fuse or breaker in the boat. No drain plug on the trim pump. The hydraulic shift setup. It's basically simple though--no belts, no front mount, no circulating pump, flywheel alternator.

I once had a Renault 16 with a similar engine. The car had all sorts of quirks but the basic engine was sound enough.

Question: I have a service manual for this--they could be downloaded until a few weeks ago. Is there a maintenance and operation manual posted anywhere? There is a grease fitting on the outside transom casting but I'm not clear what it does. Grease comes out around the bumper. It is supposed to lube the gimbel bearing? The manual is sort of vague about lots of things.

Alan

Well, I bit the bullet this afternoon and cut out a foot of soft floor forward of the engine box. The bad news is everything I could reach is wet and mostly soft. The fore and aft plywood stringers are effectively gone. I pulled out lots of soft, loose pieces whose purpose is unclear to me.

The good news is the bottom core seems solid. As does the transom.

I think there is considerable redundant structure meant to support a front engine mount and possibly a stringer outdrive, though I am not aware than Lund ever offered them.

I think I can see my way clear to sister the stringers and patch in some floor and use the boat a bit this year. To really make it right will call for some more extensive reconstructive surgery.

Now I can see that I should have cut out some floor on DAY ONE and started drying it out (!)

The lack of ventilation really strikes me. I looked at a Larsen last weekend that had a grating in the floor. Should I use a floor register or something for ventilation?

I've really appreciated all the informed input. Thanks again.

Alan

The 1970 brochure shows OMC as an option.

Both my Shell Lakes have OMC power.

As for the OMC stringers, there were actually 2 different mounting systems at least thru 1969. I am not sure when they discontinued the transom mounts. I believe by approx 1972, but I don't have a firm date. Both my boats are transon mounts with feet that bolt to the transom and in the case of the V6, a fwd centrally mounted support. My V4 hangs from the transom similar to the MerCruiser model 0 Renault.

My boat would have been in trouble had there been a front or side engine mount. The supporting structure was pretty much reduced to a collection of loose pieces. But with the Renault-based outdrive hung from the transom, which didn't deteriorate,there were no loads on that part of the boat and things stayed together.

I suppose I ought to repair the boat well enough to enable a larger outdrive to be transplanted in.....

Thanks to all who have given advice, especially jimandros.

I got the boat running and out on the water ...so here's a progress report.

Top end power is satisfactory to us, but maybe our expectations aren't too high in this regard. On the other hand, starting and idling doesn't seem up to par--though I'm not experienced with outdrives and maybe not sure what to expect. Some carb and/or ignition issues here. I notice the flame trap seems to foul the choke linkage. Timing is hard to set because the marks aren't easy to see with the gas tank in place.

Have had some electrical glitches related to the main engine-harness to boar-harness connector. I think these were resolved by spreading the split pins a bit.

The steering--original Merc rotary Ride-Guide--seems a but twitchy but there is no obvious large play anywhere I can find.

Otherwise, everything works pretty much as expected.

I can see why most runabouts are a foot or two longer.

Overall, this has been a learning experience......

am