Gubbs GT23

[OzzyC]

Where are those tanks? They should be in the stern.
This boat has all the volume towards the stern and must be loaded accordingly. The trim will improve as you ad gear in the storage compartment.

Thanks Jacques... personal involvement like this really goes a long way. I'll make sure to tell Greg about this.

[Daddy]

OK, now I am confused, the study plans say:
"We show fuel tanks under the bunks for those who install a large heavy engine on the transom but with a small engine, the tank should be under the cockpit seats. This is a matter of weight distribution and is explained in the building notes."
so I am not sure what or where the tanks should be. Also Gubbs, the study plans recommend trim tabs for planing speed, did you opt for them, I wonder if that would help you get out of the hole?

Just wonderin and confused as always Daddy (borrowed that from Dougster)

[Gubbs]

The tanks are under the cockpit floor, as far back as I could get them. I also stored all heavy gear and provisions in the rear of the boat, including water (I don't have a water tank but had portable jugs which I strapped accross the rear transom). Even with full tanks and water she was a little bow down at rest. I'm glad I did not put the fuel tank under the bunk because that would have exacerbated the problem.

I don't have trim tabs. I wanted to see how the boat ran without them before I spent the money. The boat runs fine for me, no tendancy to porpoise, and is only a little slow to get up on plane when heavily loaded. It gets up fine when light. Since at full throttle I don't reach max rpm when heavy, I will talk to my dealer about changing the prop pitch which I think will help. I am pretty sure I will never put trim tabs on the boat, and will just use the motor trim, as I am happy with the attitude when on plane.

cheers

Gubbs

[Iowa Boy Greg]

Looks great Gubbs!

IIRC, you used some heavy glass windows and fairly heavy plywood construction for the cabin? This is likely contributing to the weight distribution issue.

I was planning on building a lightweight foam cabin/roof with lexan windows and putting the tanks under the bunks. Now I'm not so sure...

BTW, after putting on some of the copper based bottom paint, we found that it was difficult to get a smooth finish. It was also fairly soft. So, we decided to go with epoxy/graphite. 1st coat: 1 oz colloidal silica, 2 oz graphite powder, 12 oz epoxy (all by volume). 2nd coat: 4 oz graphite, 12 oz epoxy. 3rd coat yet to go.

Greg

[jacquesmm]

That boat is sensitive to weights forward. We calculated the CG with 2 persons in the cockpit and most of the gear there too.
I wonder why the trim is down by the bow but now that you are aware of it, let's keep loading in the stern.
Besides that she seems to perform as expected. You did a good job, she looks good.

PS: the hull shape of the GT27 is different, we gave it more volume forward to support the weights in the cabin.

[Daddy]

I'm pretty sure that gubbs built his cabin out of the foam option so that should not have added much weight, windows maybe. I too am thinking of lexan windows, still havent heard from the window people so that is still an option. I wonder, putting only a 25 on the back of mine, she will really be out of trim, guess I'dd have to wait and see, still have not caught up with Oz. Work keeps getting in the way of work on my own boat.
Daddy

[jacquesmm]

If you look at the pictures earlier int his thread you can see the cabin made from plywood.
If you use foam sandwich or honeycomb, ti can only be better.
From the pictures, the boat looks in his lines but it is the drainage that bothers me.

[Gubbs]

The cabin was made of 1 inch foam between two sheets of 1/8 marine ply vacuum bagged. The windows are glass and were quite heavy and obviously would affect the lines at rest. The boat is not out by much, it only fails to drain about 1/4 inch of water or so that pools next to the door between the cockpit and the cabin. I can fix the cockpit so that it drains properly. I was more concerned that if water got into the bilge, which is connected to the front by limber holes, that the boat would get more nose down and water would not pool by the bilge pump. As far as I can tell, this will not happen. I have had a fair bit of water pool there after a heavy rain (I have not had a chance to seal my hatches yet!) and the bilge pump happily gets rid of it. All in all, I'm pretty damn happy with the boat!

Cheers

[jacquesmm]

Don't misunderstand, I think the boat is a success. We just try to iron out some little bugs.

[gk108]

All in all, I'm pretty damn happy with the boat!

Cheers

I like it too.
As good as the renderings in the study plans are, nothing beats pictures of the real thing. The report of the maiden voyage sounds like the boat is an excellent floating camper.