SR4 owners

MustRib · 10 March 2008, 20:53

I need a little advice on elephants trunks please.
My SR4 doesn't have one...its an old boat and one was never fitted.
I noticed that the Avon elephants trunk and the aftermarket ones seem to
involve a 100mm hole being drilled in the transom.
This seems a large hole for a relatively small transom...I would be worried about the strength of the transom with this size hole in it!
Anyone ever fitted a smaller trunk set up ?
I do have a bilge pump fitted at the moment, but just want to cover myself in the event that it fails.

thanks
Andy

Nos4r2 · 10 March 2008, 21:06

There's a guy on Ebay sells smaller trunks-about 70mm across iirc.

MustRib · 10 March 2008, 21:29

thanks Nos...
you dont know what his ebay id is do you?

Nos4r2 · 10 March 2008, 22:23

No unfortunately. I bought one from him a couple of years back and I've seen him list them regularly since so you'll find them if you keep an eye on it. Might be worth asking ADS if he's using the one I had-I didn't fit it and it went with the boat.

ADS · 11 March 2008, 02:11

Hi guys, sorry i ve been doing my dissertation

The trunk that Nos supplied has not been fitted for a number of reasons.
1. Theres a bloody great 50hp on my transom so the transom needs all the strength it can get.
2. The boat is quite old now and whilst its structurally sound I don't want to go putting any holes in a transom that probably seen some action over the years.

The solution? Well there is a bildge pump fitted, however in the event of electrical failure it obviously would work, when I find somewhere to mount it I may well fit a conventional manual jobby.

MustRib · 11 March 2008, 08:49

thanks Alex
I think our boats sound pretty similar.
There is a Yam 40V on mine....again the boat is old and I am concerned
about cutting a hole in the transom.
Last summer I contrived to get just a bit swamped off Bigbury in Devon,
and I ended up taking shelter in the River Avon at Bantham while I bailed out the boat. Apart from looking stupid - it took quite a while.
It all happened quite fast as well.
So - now I have a Rule 1000 bilge pump, but in the back of my mind
I'm thinking should I stuff the boat again big time, and the pump clog or stop,
then I have no fast way of dumping the water.
Any other SR4 owners fitted a trunk to their transom? Does it affect the
strength of the thing?

ribraff · 11 March 2008, 09:34

The other solution is to find a piece of pipe which you think will be big enough, drill the hole out with a hole cutter and have a trunk made up to fit it, the pipe can be epoxied into place with some small screws through the inside of the pipe and in to the transom, it all depends on what size hole you think you can get away with.
If you decide to go this route i can supply you with a tailor made trunk to fit.

9D280 · 11 March 2008, 09:42

I was going to fit one to my old ('82ish vintage) SR4, (had a 25) but didn't simply because I sold it to upsize before I got round to it. (And yes, I know that "pass me a bucket" feeling too.......

).

I wouln't worry too much about the strength - the hole goes in right at the join of the transom & the deck, any levarage is taken by the transom brace struts and the top / middle of the transom. It's not like you're relying simply on the transom material at the join to take all the force. You also probably have a nice strip of metal along the top to help shift the force to the braces? What I would say is if you do it, make sure the fibreglass round the hole is properly sealed!!!!!!

Also if you're worried about the size of hole, my "new" toy is fitted with a "dinky trunk" - I would guess 50-60mm dia. Whether it was fitted by Humber or Delta or a previous owner I don't know, but might be worth contacting them to see if they still make them?

Pablo · 11 March 2008, 10:59

The other solution is to fix a piece of hose pipe to the bottom of the transom, feed it over the transom an fix it just above the prop. When the prop turns it creates a vacuum which sucks out all the water in the boat. It's very efficient but obviously the prop has to be turning !

9D280 · 11 March 2008, 14:48

Won't that entrain air into your prop once the boat is bailed?

Pablo · 11 March 2008, 15:52

Quote:

Originally Posted by 9D280

Won't that entrain air into your prop once the boat is bailed?

I honestly don't know.

9D280 · 12 March 2008, 10:13

I'm only going by the nice "sooking" noise the self bailer on my Laser makes once the cockpit is dry (or as dry as its going to get on a laser!) The vacuum behind the wedge is always there, so it always sucks, whether water or air. Happens on every self bailer on every dingy......

On a similar theme could you fix a dinghy self bailer transom mounted like the pitot / depth sounder transom mounts, and stuff the hose down the wedge with half a gallon of sealant? Closing it would be irrelevant as the hose over the transom would prevent "feedback".

Still probably easier & quicker drilling for a trunk tho'........

ADS · 13 March 2008, 19:02

Dinghy self baler into the flooding hull cavity?

MustRib · 13 March 2008, 23:34

Alex...did you try fitting a self bailer into the flooding hull yourself?

Andy

Nos4r2 · 13 March 2008, 23:38

Quote:

Originally Posted by ADS

Dinghy self baler into the flooding hull cavity?

Nah. You'd weaken the floor doing that.

You could actually put a very small diameter elephants trunk over the bung hole It should drain fairly quickly-probably as fast as the bilge pump.It certainly comes in quite fast... I forgot the bung once...

IBWET · 14 March 2008, 06:47

I'm not saying this is the right way to solve your issue, just how I did it with the same boat.

I had a similar concern re strength while considering a bilge pump on a SR4, (I had a 60hp Merc). The set up I finally settled on was:

1) Blank of the flooding hull with a removable (screwed rod and internal bar) stainless steel disk. Rubber grommets cut to size for the two at the front of the hull.
2) Remove the internal sump plug.
3) Fit a bilge in the flooding section and run the hose through the sump plug hole into the boat and out over the transom.
Take the power cable through the same hole, run to the dash and switch it.

I used a whale in line pump for a water supply for a caravan fresh water supply. I found it emptied the flooding hull quickly enough> I kept waiting for it to fail after using it in the sea but it was still going strong after 8 years (as the boat got nicked it might still be working for all I know).

The benefits I found were no additional holes, no water sloshing around in the boat (wet skiers etc) as it ran into the flooding section via the sump hole.

As for space I also had a hummingbird depth sounder fitted in through the big hole, along with the pump, it was a little sore on the fingers, but it can be done.

The only concerns I would have if doing this again would be, if you don't make sure the flooding blank is water tight, over night the water will fill the flooding section come up through the internal sump plug and fill the boat, no real problem as the bilge clears it. Make sure your battery terminals are above the filled boat water line, if they get submerged they turn the inside of the boat into a battery..

any metal in it will dissolve over night, just another little experience..

.

I left the hose and power line free in the internal sump hole, if I were doing it again, I’d silicone them in place to seperate the flooding hull and the inside of the boat.

Only a suggestion, but it worked well for me for a number of years..

MustRib · 16 March 2008, 13:05

some interesting ideas here guys thanks...
I see that RibShop is selling a 70mm trunk kit.

As I am inexperienced with using fibreglass matting I was thinking I could use Marine epoxy to seal the hole in the transom, and also use it to seal the plastic drain tube in.

If that wont work, I'd appreciate some words of wisdom as otherwise I will have to take the boat to someone who can fibregalss!

thanks
Andy

Nos4r2 · 16 March 2008, 15:37

Quote:

Originally Posted by MustRib

some interesting ideas here guys thanks...
I see that RibShop is selling a 70mm trunk kit.

As I am inexperienced with using fibreglass matting I was thinking I could use Marine epoxy to seal the hole in the transom, and also use it to seal the plastic drain tube in.

If that wont work, I'd appreciate some words of wisdom as otherwise I will have to take the boat to someone who can fibregalss!

thanks
Andy

It's probably not what you want to hear but I'd take it to someone who can fibreglass. Holes in transoms aren't the ideal thing to cut your teeth on as it could be a major issue if you do it wrong.Start on something easier!. I still can't do it well...

MustRib · 16 March 2008, 16:42

thanks Nos....
will probably be expensive I suppose.

ADS · 20 March 2008, 18:30

I was always told 'if you can masturbate you can laminate'!
Theres a guy round my way that does fibreglassing mainly making garden gnomes although he does do marine, he loves abit of cash in hand and has done loads of work for me over the years.