Transom problems with Larson 186 SEI I/O Bowrider

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Getting ready to grind some gel coat right now (ugh) to tab those edges. They're not quite a smooth as they appear in the pick, so I'm going to apply some PB to make a smooth transition.

Fat Fanny, I didn't reinforce under the pedestal areas. There is a 3" wide fiberglass bulkhead just an inch or two forward of where the pedestal will rest, and I plan to build pedestal platforms out of two layers of 3/4" plywood. The platforms will be PB'd and glassed to the deck and the pedestals will be bolted to the platforms with bolts and T-nuts so there is no thru-deck holes.

Time to go tab in the bilge area...

Jim

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

The bilge area is tabbed in and it looks pretty good, I think. I PB'd the edges and then covered them with a 6" wide layer of 1708. That stuff is so nice to work with... After the resin kicked, I cut holes in the deck for pouring foam.

Tomorrow the foam goes in!

Jim

 

[SMullenMaine]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Hi Jim,

I haven't posted for a while, but my floors are in and I poured foam last week... it wasn't nearly as exciting as I'd thought it would be... I heated the garage to 80... as the manufacturer recommended... waited til the boat and the 2 parts were up to temperature and then went for it... I mixed a pint of A & B for each pour... thinking that I would get 1cf from each batch... I wished that I had a paint mixer on my cordless drill so that I could have mixed it up more thoroughly & quickly... but there seemed to be plenty of time.

I had six sections of sub-deck so I would pour a batch in each section and would be ready to go around again in about 40 minutes which is what the mfg said was the ideal re-pour time... I had not tabbed the sides of my floor to the hull because I wanted to see the foam filling the edges...

All in all, it took almost twice as much foam as I expected... not sure why... I thought I was pretty good at geometry... The foam seemed to expand correctly... luckily, I had enough to finish it.

I'll post pics to my thread soon.... hope yours goes well!

Steve

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

I'm hoping I can get the garage warm enough. It's going to be close...

Love to see pics of your boat!

Jim

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Had a hard time getting the garage warm enough for foaming. Eventually I decided to cover the boat and put a space heater under the cover. That did the trick! I got the boat up to 85 degrees, and a small fan blew air into the hull cavities to warm up the boat. It was a bit cramped working in there, but at least I was able to do some foaming.



Foaming wasn't too difficult, except for figuring out how much to use. I was surprised how quickly the stuff set up; I had a couple of buckets that set so hard, I couldn't clean them out after using them once.



After foam the hull, I cleaned out the holes by running the hole saw back into the holes. Then, I cut out what I could with a utility knife. I found this thing (below) that worked great to clean out the foam from the holes so I could peanut butter the wooden 'pucks' back in. It was a 2" paint stripper disk that attached to my drill. It cleaned out the 2 1/8" holes really nicely.



Jim

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Here's what it looks like with everything PB'd back in. I think I'll need to do another pass with some more PB. I think some additional filling will be needed. Even so, I'm happy to get the foam in.



I was surprised how little foam I used. I ordered three sets of 16 lb. kits of foam, and I only used about 1 1/2 of them. Next big step will be to glass in the deck and to build the bases for my pedestal seats.

Jim

 

[jbcurt00]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Nice work, looks great!

 

[jsturvey]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Lookin' good! Have you decided what direction you are going to take with the floor....carpet, gel coat?

BTW, I don't know how I missed it, but that boat has a 350ci Mag engine? That thing must scream across the lake with that kind of HP!

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Nice work, looks great!

Thanks!

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Lookin' good! Have you decided what direction you are going to take with the floor....carpet, gel coat?

BTW, I don't know how I missed it, but that boat has a 350ci Mag engine? That thing must scream across the lake with that kind of HP!

Thanks, I'm feeling pretty happy with how it's turning out. We haven't decided about the floor. I thought I had settled on using Durabak (one or two coats of rough covered with a couple coats of smooth), but now I'm wondering about using gelcoat, and covering parts of it with HyrdoTurf or SeaDek. I haven't seen enough pictures of the latter to have a good sense of how it might look, though. Gel coat and snap-in carpet would be my preference if money were no object, but that seems like one of the pricier options. If I had to pick right at this moment, I'd probably choose Durabak, but I don't really have to decide for several weeks, so I'm going to think about it a bit more.

Yes, the engine is a 350 Mag with an Alpha One Gen 2 leg. It can move across the water when it's opened up! It had a little issue with chine walking when it hit about 48-50, but SmartTabs took care of that. It's really solid feeling when it's moving, although I don't really do it all that much. We do get a pretty good hole shot, though. Pops water skiers right up out of the water.

Jim

 

[jsturvey]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Thanks, I'm feeling pretty happy with how it's turning out. We haven't decided about the floor. I thought I had settled on using Durabak (one or two coats of rough covered with a couple coats of smooth), but now I'm wondering about using gelcoat, and covering parts of it with HyrdoTurf or SeaDek. I haven't seen enough pictures of the latter to have a good sense of how it might look, though. Gel coat and snap-in carpet would be my preference if money were no object, but that seems like one of the pricier options. If I had to pick right at this moment, I'd probably choose Durabak, but I don't really have to decide for several weeks, so I'm going to think about it a bit more.

Yes, the engine is a 350 Mag with an Alpha One Gen 2 leg. It can move across the water when it's opened up! It had a little issue with chine walking when it hit about 48-50, but SmartTabs took care of that. It's really solid feeling when it's moving, although I don't really do it all that much. We do get a pretty good hole shot, though. Pops water skiers right up out of the water.

Jim

That Durabak does look interesting...I know friscoboater used it on the 19' Glastron restoration; there is some video of it on his YouTube channel. It definitely has that textured look to it.

I definitely understand hauling across the water at that kind of speed. I've had my MC up to around 48, but still can't bring myself to take it to WOT. Yikes!! A 186 SEi with that kind of HP is not something you see every day. You've got yourself quite a boat, Jim.

Joe

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

OK, boat construction gurus, I could use some help. I'm thinking ahead to building bases for my seat pedestals similar to what others have done (and shown in friscoboater's Sea Ray project). I am planning to join two thicknesses of 3/4" plywood, which will be peanut buttered to the deck, then fiberglassed down with some kind of biaxial and/or CSM. The edges of the bases will be cut on a 45 degree angle.

One of my concerns is the strength of the bond of the base to the deck; I'm especially concerned because I'm installing a taller, adjustable pedestal for the driver's seat (so I can see over the windshield better). Will the seat base be strongly adhered enough to handle the leverage caused by the longer pedestal? I hate to have the thing pull off the deck while underway! I'm not small -- 6' 3" and 220 lbs., so I want it to be solid.

What would be the strongest way to glass in the base, outside of the peanut butter? A couple layers of 1708? More layers of something lighter (e.g., 1208)? CSM? I'll be either gelcoating the deck or using Durabak (it won't be covered in carpet), so I'd like at least the topmost layer to look nice.

Finally, any opinions on the shape of the bases? Most that I've seen are square, but I was considering octagonal or even round bases. I don't know what that might do the strength of bond to the deck or if a non-square shape will be harder to drape with fiberglass.

What do you all think?

Thanks,
Jim

 

[Woodonglass]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Shape really not an issue. Size is. I'd recommend 16" minimum. Wish we had known this earlier, It would have been best to use cross bracing on the stringers at the seat locations under the deck for extra support. If you have a 3/4" deck then you'll be fine. PB and 8" 1708 tabbing X2 will suffice.

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

The decking is 1/2" plywood. I thought about reinforcing the underside, but decided against it for a couple of reasons. First, the original pedestals were mounted with lag screws into the deck. As far as I can tell, the deck was treated with some resin, but it didn't appear be glassed. Under the deck beneath the pedestals was a 12" square aluminum plate (maybe 3/16" thick) that the lag screws bit into. The seat was pretty solid, so I figured my scheme (below) would be even stronger.

My deck is also 1/2" plywood, but I have 1.5 oz. CSM underneath and the surface will have two layers of CSM and one layer of 6 oz. cloth. Added to that are the 1.5" thick pedestal bases I want to construct. The metal base of the pedestal has a 9" diameter.

My initial thought was to construct a square base that, on its top, would be about one inch wider than the metal pedestal ring; in other words, 10" square. With 45 degree angle edges, the bottom of the plywood base would be about 13" square. That would give me 169 square inches of contact area between the deck and the plywood base. I could get the same contact area between deck and the wooden pedestal base from a circle whose diameter is 14.5" diameter.

Increasing the square base to 14" on each side would give me 196 square inches of contact area, the same as a circular base with a 16" diameter. Going even bigger, a 16" square base would give me about the same contact area for PB as am 18" circle, about 256 square inches.

From an appearance standpoint, I think a circular base would look pretty nice, but the circle offers less contact area with the deck (compared to a similar size square) for adhering with PB. A circle would have less likelihood of being a 'toe catcher' as people move around the boat in bare feet. Also, if I'm standing while driving the boat, I don't want to have the seat base sticking out so far that half my foot is on the deck and half on the seat base. I think I will need to mock up some different sized squares and circles and see how they look under the seat and pedestal.

Regardless of the shape, I'll cover the plywood base with two layers of 1708, extending 8" onto the surrounding deck, as WOG suggests. I may add an additional layer of the 6 oz. cloth, just so the texture is the same as the rest of the deck.

I'd be interested to hear from others who have built these sorts of pedestal bases, to hear how they've held up if you encountered any problems.

Thanks,
Jim

 

[Woodonglass]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Here's and example...

How Tall is your pedestal going to be?

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

This is the pedestal I got:

14"-18" Adjustable Medium Seat Pedestal - Garelick 75637 - iboats

Jim

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Here's and example...

How Tall is your pedestal going to be?

And that is just the sort of base I planned to make. Is that a picture from Friscoboater's Sea Ray?

Jim

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

(Deleted cuz I messed it up....)

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

Let's try this again...

Still trying to figure out these seat bases. I cut a couple of different bases out of pink foam board to see how they might look. One is round, with a diameter of 16"; the other is square with 14" sides. Both have about 200 square inches of area that will be in contact with the deck, so they should hold to the deck equally well.

Pictures immediately below are of the square base. (The black line 1.5" from the perimeter of the mockup base defines the area of the top surface if the edges are cut on a 45 degree angle to flare down to the deck.)



Pictures of the round base in the next post.

 

[JASinIL2006]

Re: Transom problems with Larson 186 SEI I/O Bowrider

And here's the round base. (It also would flare in on a 45 degree angle, but I didn't draw that in. Just imagine a line about one and half inches in from the perimeter to picture the size of the upper surface.)



What do you all think? I kind of like the look of the round base, but I have no idea how I'd cut a circle with a 45 degree beveled edge.

Jim