loose block

water rat

Member
Just purchaed a 1981 fish in very good condition When I got it home after a trailer trip of 160 plus miles I heard what sounded like something loose in the hull. . There is no inspection port..and given the boats age I surmise that a block came loose during the trip even through the boat was well cushoned with full bunk beds on the trailer... augmented by swimming pool noodles. Any major consequences if I use the boat in this condition?
 
The loose thing rattling in there won't CAUSE any troubles... but it means you have some piece of hardware that does not have its backer block. That piece is going to have its screws rip out of the deck.
 
Hi there,

Without knowing what is rattling it's hard to say what the consequences might be, but the boats are so simple that it is hard to imagine anything catastrophic happening.

If it were my boat, I would try checking all of the screws to make sure they are tight. If a backing block split and or let go, I would imagine the screw would just spin.

You might think about an inspection port in front of the daggerboard slot anyway, as it is great for keys, mobile phones, etc.
 
Had a boat that tied too tight and the block was loose after the tension was released. Put a port in.

You will have a deck or hull flexing and if really loose they could rotate and tip over

The blocks make the deck and hull ridged, they are not related to the backer blocks which are separate pieces of wood (1981) glassed in the area where screws go in.
 
all screw tight excepting the halyard fairlead next to the mast. they are not very loose but can be turned and have no stoping point. any idea how to fix this without riping out a portion of the deck. It's a long shot but if the block is still there the screw holes (1981) may be worn and a size larger screw might bite the block if it is there...just guessing on that
 
bbacking blocks were reportedly glassed in..but every thing is tight except the ones in the fair halyard next to the mast and it takes an effort to turn them perhaps an indication the holes in the block have enlarged since 1981.
 
Had a boat that tied too tight and the block was loose after the tension was released. Put a port in.

You will have a deck or hull flexing and if really loose they could rotate and tip over

The blocks make the deck and hull ridged, they are not related to the backer blocks which are separate pieces of wood (1981) glassed in the area where screws go in.
Many thanks for the glass/block info. Since the blocks are foam..wouldn't they be silent or near silent. ..perhaps in my old age I was hearing things. If one of them is lose is there any way to re-attach it without cutting. I think the answer is no but I had to ask
 
all screw tight excepting the halyard fairlead next to the mast. they are not very loose but can be turned and have no stoping point. any idea how to fix this without riping out a portion of the deck. It's a long shot but if the block is still there the screw holes (1981) may be worn and a size larger screw might bite the block if it is there...just guessing on that

If you are sure the block is still there...

pull one screw , rotate the fairlead and replace the screw in the deck with a much longer screw (gives you a handle on the block so the block won't fall and get lost) then pull the other screw to get the fairlead out of the way.

Drill out the empty hole larger. Maybe 5/16 inch. Buy a dowel and epoxy dowel in to fill the hole. Cut off flush with the deck.
That dowel will now hold the block securely so you can pull the long screw.
Drill and epoxy dowel in the other hole.
Now you can drill into the dowels for putting the fairlead mounting screws back.
Screw the fairlead down snug then pull the screws.
Soak the holes with appx 12 drops of thin cyanoacrylate (crazy glue, not gap filling or thick) Let dry for an hour. This will make the dowel wood waterproof and it can't rot. It will also harden the material so it can withstand more load before the screws pull out.
Screw the fairlead backd own.
 
A block that is just rattling around loose would generally be replaced with a new piece of wood, epoxied in place and treated for rot resistance (coat with epoxy or soak with a mix of mineral spirits, spar varnish and linseed oil AFTER gluing in place)


I generally prefer slow cure epoxy because it soaks into the wood surface better and longer cure time = longer molecular chains and stronger glue. Not as important here as in some other applications.
 
The wood backer blocks were only glassed in to the extent that there is a strip of fiberglass over them like a Band-Aid holding them to the
bottom of the deck. As the blocks age and fall apart they pull away from the fiberglass strips. They need replacement with the exception
of the bow handle block. The bow handle block is a two inch thick chunk of packing crate wood, this can be plugged with dowels and re drilled.
The standard location of two inspections ports allows access to all blocks, however, the deck pulley/fairlead is a really long reach. The wood
screws can be replaced with stainless steel bolts, locknuts and fender washers. I go with a 8 inch port behind the splash rail and a 6 inch port
four inches from the stern. The 8 inch port allows me to store lines and generally get at stuff inside the hull. The deck can be partially split from the
hull for access but I've found this a bit tricky and not recommended. Depending on how well the factory did it's job you may come to a point where the seam cannot be wedged open. Button it back up with fiberglass and resin because further attempts will crack the deck.

My first boat had loose foam blocks and while it sailed just fine, it's not going to be good for the life of the boat. They keep the boat from
flexing more than it already does which is quite a bit near the center of the boat. If loose you will hear a clunk because they are quite heavy
when water logged.
 
Had a boat that tied too tight and the block was loose after the tension was released. Put a port in. You will have a deck or hull flexing and if really loose they could rotate and tip over. The blocks make the deck and hull rigid, they are not related to the backer blocks which are separate pieces of wood (1981) glassed in the area where screws go in.
The top photo shows what you'll see looking forward from the cockpit. The white foam in the distance is a Styrofoam block for deck reinforcement just forward of the mast step (in the middle). The white Styrofoam blocks on each side are jammed-in by the factory, and are intended as reinforcement for the deck. The tan globular material (top and bottom) is the "glue" that holds the Styrofoam blocks in place.

If your Styrofoam blocks are loose, you'll hear dull clunks as the boat is turned over. Wood blocks make a sharper sound. My right Styrofoam block shows a scant application of "glue", and did become separated. I still need to work on that, but if you do a search here for making a "spring", and you'll see what I'm substituting in the meantime. That "spring" still needs to be moved up and forward to do its intended job.

P8260064-001_zpswx0kjygl.jpg


I've handled a lot of Styrofoam blocks that supported swim rafts over summer, and can't say I've seen any that weighed noticeably-extra from that use. More-experienced Sunfish owners, please correct me if I'm wrong. The "glue" does get weak when saturated with water, however, and has to be removed and replaced (best) with a two-part foam. I used Great Stuff instead, and slopped Rustoleum paint over it. Great Stuff is now sold in a variety of products. Check the Internet for what's best, and available today.

If your Styrofoam blocks are loose, you'll hear dull clunks as the boat is turned over. Wood blocks make a sharper sound. Notice at the top-right, in a different Sunfish, that the factory did not have a consistent spreading of the "glue".

pi0jN1p.jpg
 
Many thanks.Did you install a port in the forward cocpit bulkhead as well as the deck forward of the splash rail?
A 6-incher is AFT of the splashrail. The cockpit opening is described fully--search the word "ultimate".
 
'Just stumbled on a 2-part foam-fix that I would have tried earlier. Note the author's use of "slings".


Working through the bottom (or cockpit) would go especially well if the Sunfish were on "slings" (using the fire-hose advertised here ;) —under "work station").
Sunfish For Sale | Page 2 | SailingForums.com
 

Back
Top