Mustang 24 rebuild

[giddyup58]

Finished the locker floor repair.
IMG_4136.jpg IMG_4145.jpg

The top was epoxied down, glassed to the hull with epoxy on top, and a 25mm epoxy glue cove underneath.

Now I'm happy.

Just need to sort out the problem of the burst water tank, then get onto a bit of upholstering...

[giddyup58]

You may recall the the Mustang has been put seriously onto the back-burner over the past few months, with my obsessing over the HH 1600 SO ski boat and the refurbishment of the Ventura.

I'm very pleased to say that I'm back onto the Mustang.

Obviously from the past couple of updates, the 300 Suzi has been removed, converted from an XXL to an XL and refitted after the pod was modified.
The damage caused by my slackness and the anchor winch has been repaired and future proofed, and the trailer adjustment will be happening soon...

But the biggest hold up with actually finishing the boat is the upholstery and the trim. The vinyl on the new seats is totally unavailable. There are several vinyls that are close, but nothing that is exactly the same.
I have now accepted the fact that I am going to have to have the new seats recovered in order to have the cockpit look like it has been thought about and not literally thrown together. I think the end result will far outweigh the inconvenience and cost of recovering perfectly good seats...

For the interior, I decided to go with the light grey backless carpet that we used in the Ventura for the ceiling and charcoal for the cabin sides and storage shelves. Lessons were learnt on the Ventura, so I made a quick MDF mold of the outline of the ceiling and used that to cut out the carpet:

IMG_4147.jpg

It worked really well. One piece, 2m wide and near 3m long, up in one go, no joins and no creases. Quite happy with it:
IMG_4151.jpg IMG_4153.jpg IMG_4154.jpg IMG_4155.jpg

Just need to get a bit more charcoal carpet to finish the main cabin, then lots more grey to do the transverse bunk room. That will be lots of fun!

The whole process is made so much easier and cheaper by using a suction gun and spray contact purchased in bulk. It is wonderful that the carpet actually sticks and stays when put in place.
Those stupidly expensive spray cans of contact are really not suitable for doing this type of work. They just do not go far enough and the cost would end up prohibitive.

The soft covers (cushions) will be getting done soon. The piping is blue, and it just doesn't work. Needs to be black, which will (should), then tie the cockpit and the interior together.

We'll see.

[Chimo]

Really great job.

[giddyup58]

Seeing the Ventura is done, I managed to spend some time on the Mustang.

It hasn't been in the drink for months, because I never managed to get the trailer looked at.
A couple of suggestions from some kind folk here steered me to make a few phone calls to alleged set-up geniuses, but unfortunately, none replied.

My poor long suffering mate Cyril (the friendly outboard mechanic), made a few suggestions re trailer set-up.

I took his advices and spent 5 hours on the weekend re-adjusting the rollers and adding keel rollers.
Nasty work for an old bloke with a bung knee, but I got it done and managed to talk No.1 son (now the proud skipper of the Ventura), into coming for a run.

On the way to the ramp, we stopped at the Weigh Bridge off the Port of Brisbane expressway, and still attached to the car, it weighed in with half fuel (160 litres and no water 150 litres), at 2540kg. So fully loaded we are well within the 3,500kg limit.
Given that the trailer is 840kg, the boat on the water on the day weighed 1,700kg.

Put in at RQYS, where the ramp is never busy, and launched and retrieved several times with not too much difficulty.
On a couple of occasions, the 2 front roller arms were staying perpendicular, which was upsetting the loading process. I think perhaps replacing the rubber stops under the roller arms may well fix that. So at least it is now useable. Although I do think fully keel rollered and skids will be the go.....

After the pod rebuild and outboard modifications, I was interested to see if the performance/handling was in any way improved.

Oh Boy.

It leapt out of the water like never before. We had noticed that the trim limiter had been set too high at it's lowest setting, so we were not getting enough tuck under.
Well, that's not the case anymore, and it is much better.

It still has the typical 24 degree deep V problem of laying into the wind, but a little down tab on the low side side quickly fixed that.
Trimming out was a revelation.
Lifting the motor (raising the height of the prop), has all but cured the porposing, and trimming out has had a marked effect on ride and speed.
It now feels more stable and somehow lighter, and is definitely quicker.
It still porpoises, but at least I can get some +ve trim out before it starts, which has made a big difference...

Previously, we got a best speed on a flat day on the river at 42.1knots
Now, on a choppy Moreton Bay, we got 44.8 one way and 45.2 the other.

It feels as if it could come up another hole...

[giddyup58]

Hi all.

We have been using the Mustang a bit over the past few weeks, and decided that I have to stop it porpoising as it is tiring and uncomfortable.
At high speed, the cav plate was only just visible, and small amounts of trim would cause the dreaded porpoising. I could get away with about 25% +ve trim.

So I had a chat with ol' mate Cyril, and we decided to come up 1 more hole, fill the front water tank (100 litres) and 2/3 fill the fuel - 210 litres.

Took it for a run yesterday on the river. I can't believe it, but the porpoising has totally disappeared. I can trim the motor out so far that it throws a rooster tail behind the boat, with no porpoising. I can trim +50% with no slip and with NO ill effects, and top speed has climbed a bit more to 46.2kts. (with tide and wind...)

3,500rpm = 25kts @ 24lph = 1.91km/l
4,000rpm = 27kts @ 30lph = 1.66km/l
4,500rpm = 34kts @ 40lph = 1.57km/l
5,000rpm = 36kts @ 50lph = 1.34km/l
5,500rpm = 40kts @ 67lph = 1.10km/l
6,000rpm = 44kts @ 95lph = 0.86km/l
6,100rpm = 46kts @ 112lph = 0.75km/l

The most economical speed is 3500rpm, but the most economical fun is at 4,500rpm. The boat really settles nicely at speeds over 30kts, and the biggest jump in efficiency seems to be between 4,000 and 4,500 - 7 knot increase for 500 rpm, as opposed to roughly 3-4 knots per 500rpm just about everywhere else.

And the beauty of that speed, is the hull is so aggressive, the speed can be maintained in quite heavy conditions...

Luckily, now I do not have to fit the permatrim.
As has been discussed many times on these boating forums, foils are best seen as a "bandaid" for an incorrect design/set-up.
Best practice is to change set up - engine height, weight distribution trim angles etc. to cure the porpoising and if that doesn't work, fit a foil.

Setting up this boat has been a chore.
You will recall that we had to try about 5 propellers before we settling on the genuine Suzuki 3x16x18.5 as the best prop, change the leg of the motor to an XL from an XXL, redesign the pod height and play with weight distribution to get to this point. And thankfully, no foil...

The boat would be horrible without the trim tabs, as there is so much torque generated by the motor and the V is so acute (24 degrees), that on flat calm water she always runs portside depressed. Which is a bit annoying, and which a foil may well fix, but I'm ok to put the port tab down a touch to level things out...

Now that it is finally sorted out, it's time to finisht the rest.
Hopefully, some stainless and upholstery work in the next couple of weeks, then I may get into finishing the teak work.

[ericcs]

Hi all.

We have been using the Mustang a bit over the past few weeks, and decided that I have to stop it porpoising as it is tiring and uncomfortable.
At high speed, the cav plate was only just visible, and small amounts of trim would cause the dreaded porpoising. I could get away with about 25% +ve trim.

So I had a chat with ol' mate Cyril, and we decided to come up 1 more hole, fill the front water tank (100 litres) and 2/3 fill the fuel - 210 litres.

Took it for a run yesterday on the river. I can't believe it, but the porpoising has totally disappeared. I can trim the motor out so far that it throws a rooster tail behind the boat, with no porpoising. I can trim +50% with no slip and with NO ill effects, and top speed has climbed a bit more to 46.2kts. (with tide and wind...)

3,500rpm = 25kts @ 24lph = 1.91km/l
4,000rpm = 27kts @ 30lph = 1.66km/l
4,500rpm = 34kts @ 40lph = 1.57km/l
5,000rpm = 36kts @ 50lph = 1.34km/l
5,500rpm = 40kts @ 67lph = 1.10km/l
6,000rpm = 44kts @ 95lph = 0.86km/l
6,100rpm = 46kts @ 112lph = 0.75km/l

The most economical speed is 3500rpm, but the most economical fun is at 4,500rpm. The boat really settles nicely at speeds over 30kts, and the biggest jump in efficiency seems to be between 4,000 and 4,500 - 7 knot increase for 500 rpm, as opposed to roughly 3-4 knots per 500rpm just about everywhere else.

And the beauty of that speed, is the hull is so aggressive, the speed can be maintained in quite heavy conditions...

Luckily, now I do not have to fit the permatrim.
As has been discussed many times on these boating forums, foils are best seen as a "bandaid" for an incorrect design/set-up.
Best practice is to change set up - engine height, weight distribution trim angles etc. to cure the porpoising and if that doesn't work, fit a foil.

Setting up this boat has been a chore.
You will recall that we had to try about 5 propellers before we settling on the genuine Suzuki 3x16x18.5 as the best prop, change the leg of the motor to an XL from an XXL, redesign the pod height and play with weight distribution to get to this point. And thankfully, no foil...

The boat would be horrible without the trim tabs, as there is so much torque generated by the motor and the V is so acute (24 degrees), that on flat calm water she always runs portside depressed. Which is a bit annoying, and which a foil may well fix, but I'm ok to put the port tab down a touch to level things out...

Now that it is finally sorted out, it's time to finisht the rest.
Hopefully, some stainless and upholstery work in the next couple of weeks, then I may get into finishing the teak work.

well done, perseverance paid off in the end!