Family 4 update (slow boat? leaning to one side? water in foam?)

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dconnx
Posts: 31
Joined: Thu May 18, 2023 9:27 am

Family 4 update (slow boat? leaning to one side? water in foam?)

Post by dconnx »

Hi all,

Just an update on our family 4. A number of people gave me good advice here a few weeks ago.

Our boat was slow, leaning to one side in the water and I found water in the foam in holes that were in the floor. Also I had put the boat into a sea marina and only painted the hull with gloss paint because I was concerned about poisons and harm to marine life. One fellow (dellquay13) did tell me things would quickly start growing on the hull. He was right.

On all those topics (but not in that order): -

1) After a couple of months at sea there was LOADS of growth on the boat (green slime weed stuff, hard white spots (maybe little shells) and patches of grey growing. I used a high pressure power hose to remove it (time consuming). I've painted the hull with Seajet 021 "environmentally friendly" antifoul so it'll be interesting to see what it's like in the next 2 months.

2) The boat was leaning to one side because I had 2 X batteries in the rear starboard box and a backup 6HP engine on the same side. I've moved the 2 X batteries to the port side and used 50mm2 cables from one side to the other - it floats level now.

3) The foam: I had holes in the floor and I know rain had made its way into the boat. It turns out the holes were the original holes where Shetland boats sprayed in the foam when the boat was made but over the years, before I got the boat, the blanking caps in the holes disappeared. I made a couple of bigger access holes in the floor - one right at the stern in the centre and dug the foam down to the bottom (I thought if there was water this was the best place to check). BTW the floor is a few mm of fibreglass and then 1/2" plywood and then foam. I didn't see any stringers but I only made a couple of access holes (rear one about 8" diameter now). The foam was very dry and I easily sliced it out with a paint scraper. At the bottom water appeared. I removed it with a wet & dry vacuum. Day after day more water appeared. The same when I made a hole in the cabin. I say I've removed 10 litres to 20 litres of water (completing guesstimating now). Even the other day I can see water appearing (but not lots of water anymore). I then got a couple of circle sealed inspection panels/hatches and, using a jigsaw, cut my holes into the right circle diameter and installed the panels so I can get access again when I need.

4) Slowness: I didn't know anything about tilt so I was probably plowing the boat into the water with the engine dropped to the lowest position. But also my engine was horrible (an '80s or early '90s 60HP mariner) and I was very concerned that it was going to let me down (I'd replaced the water impeller, had to use a carb repair kit because the top carb was leaking fuel into the air box, My fuel line did break where it attaches to the engine fitting when I was at sea but luckily I fixed it then & there and then quickly bought myself a new fuel line with bulb). Rather than keeping going with that I gave up and now installed a new 50HP Suzuki (which is probably worth multiples of the price of the boat but there is something very nice to have confidence that the engine will always work when we need it). I don't know about top speed yet because I have to break the engine in over about 10 hours. The family 4 itself is doing a very good job at being at sea and does feel safe (but I don't venture out in any kind of bad wind or weather).

The boat is back in the sea again now but that was a few weekends of work (not to mention money :-) )
blebrocq
Posts: 106
Joined: Thu Oct 20, 2022 12:24 pm

Re: Family 4 update (slow boat? leaning to one side? water in foam?)

Post by blebrocq »

Well done, I presume the new engine is 4 stroke.
Bob
dconnx
Posts: 31
Joined: Thu May 18, 2023 9:27 am

Re: Family 4 update (slow boat? leaning to one side? water in foam?)

Post by dconnx »

Yes 4 stroke now and very quiet and smokeless. Funny - the Suzuki 40HP, 50HP and 60HP are the exact same engine (weight, cc, etc) just a choke plate (smaller hole smaller engine) and, critically, a change to the computer (and almost a thousand between each 10HP so I typically picked the middle option). The new engine weighs 104Kg and the old Mariner 60 was probably heavier so that was a big of pulling and tugging for my son and I.
dellquay13
Posts: 556
Joined: Tue Mar 15, 2011 7:45 am
Location: Pequod, F4 mk4, Milford Haven Marina

Re: Family 4 update (slow boat? leaning to one side? water in foam?)

Post by dellquay13 »

With that engine you should be able to get on the plane at about 13-14kts in fairly smooth water, without too much extra weight aboard you should get about 20-21kts max in the same gentle conditions, and you should be able to throttle back to about 80% power and cruise at a nice 15-16kts without it falling back off the plane.
Try playing with the trim when on the plane to find the sweet spot, you will get your best speed just before you trim out too far and start porpoising.
I went for the Yam F70a motor as it is the max rated power for the F4 mk4, but the lightest on the market. Being based on the 50hp power head but tuned to max power and a higher max rpm it is thirstier than the 50 and 60hp versions, and I think a bit bit thirstier than other brands of 70hp which aren’t as overturned, but I may be wrong. Weight was the most important factor after reliability for me, as the 536/F4 hull was designed for much lighter 2stroke outboards.
I don’t know the seajet eco antifouling you have used, but I have found Hempel tiger xtra to be very effective on my side of the Irish Sea, although it is a traditional self eroding a/f and designed to be not a hospitable environment for aquatic life to adhere to, being largely copper based.
I have now sold my 1989 F4 mk4, 2015 70hp 4str Yamaha. Milford Haven. I proudly owned it for over 20 years, before changing to sailpower and a yacht...
captainbadger007
Posts: 6
Joined: Sun Apr 06, 2025 8:15 pm

Re: Family 4 update (slow boat? leaning to one side? water in foam?)

Post by captainbadger007 »

this sounds like the same issues i have although ive not been out on the water yet , there is a channel down the middle of the boat is this ment to be full of foam as well, i was told by the seller that it was clear , because when you put the anchor rope in its hold the water from the rope will flow through the boat to the drain plug , we put some water in the hold and it came out just after the towing eye to pull the boat on the trailer , dose anyone one know where the water in the cabin can go to as untill we took the foam out its just sitting there
dconnx
Posts: 31
Joined: Thu May 18, 2023 9:27 am

Re: Family 4 update (slow boat? leaning to one side? water in foam?)

Post by dconnx »

For me, when I got the Sheland family 4 there was a small hole in the cabin floor. it was a pretty neat little hole and I learnt, from someone on this forum, that the hole should have a plug and the hole's purpose was an original filling hole where the foam was injected into.

The hole plug must have been lost over the years and there was water under the floor in the cabin - quite a bit of water. I initially cut two square holes with a jigsaw with the holes centered in the middle (port -> starboard) with one near the door and sink and the other more forward towards table mount. (The floor is fibreglass on plywood. I later turned the square holes into circular holes and installed two maybe 5" inspection panels (these are not expensive from Marine suppliers and look good when installed - they provider a watertight seal too).

I removed an amount of foam from the holes (dug it out with a paint scraper - very easy) and I sucked out water over time with a wet and dry vacuum cleaner - any bilge pumps I tried just can't get the water down the bottom out. I did have to go back day after day as the water kept re-appearing. On the plus side the foam didn't just get completely waterlogged i.e. when I dug a bit of foam out with water everywhere it was still quite light and dryish.

I've read that the way the foam really gets damaged is through water ingress and then cycles of freezing and defrosting - this is a bit hard to avoid I suppose but, again, for me the foam still seems ok and not really bad so this is where I got to and where I'm at.

Foam in a boat does seem like a good idea - if all is as it should be a Shetland might be able to take on a lot of water and just not sink and that's a nice thing to think about (I think that's why Boston Whalers are considered unsinkable boats due to their use of foam in the body too).

Derek
captainbadger007
Posts: 6
Joined: Sun Apr 06, 2025 8:15 pm

Re: Family 4 update (slow boat? leaning to one side? water in foam?)

Post by captainbadger007 »

this is the same as we have , i did cut a section out of the floor by the door as water was under the floor , i cant see how it will make its way to the stern and then the pump , the channel in the middle was also filled with foam , i dont know if this is meant to be this way and would like to know , if anyone can throw some light on it i would be grateful, as i dont know what to do at the moment about where the water is going to go , i believe the water is coming in from the rubbing rail as all the screws are perished , also some of the fixing around the craft are not to clever either
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