PG25 or GS28

[TomW1]

Thank you everyone for your amazingly informative responses.

The build time of the Panga seems very fast in the study plans - is it significantly faster than some of the other boats and is this because only 2 stringers?

Working 9-5 could 2 people complete a basic Panga 25 in a month?

First I would not scale the PG25 it needs to have every dimension scaled due to its shape. Okay after running twin 40's or 80 HP through my calculator you would have a top speed of high 20's, low 30's. Cruise will depend on the prop you get, the load you have, etc, it should be about 1/2 throttle or a little less. Once you get on the water you will know, every boat is different.

Good luck

Tom

This is good news Tom. Does your calculator say what speed it would do with a single 40? Or one trimmed up?

One 40 would allow you to run at displacement speed, 7-10 mph at a cruising speed. A little higher at full throttle say up to 12 mph, but you won't get on plane. Again this will depend on how your boat is loaded.

Tom

[Johnston]

I have been reading over some other Panga builds.

I do think the PG 25 will suit my needs, some if the comments about it being good in chip have satisfied me there.

I do have a question for the designer .... I read somewhere that he commented on one of the early PG20’s built that it might benefit from chine flats but this would complicate the build...

Is it possible to elaborate on why chine flats would help and how difficult would they be to add to add to a build?

Now that the running pictures are posted, I went back through all the others and it is impressive.
Jazmine's picture album is like a boat building course in pictures, very nice.

The boat looks great, congratulations, beautiful job.
I am very happy about the comments from your friends. I have to admit that I tweaked the traditional lines a little bit and I love the comment that it drives like a sports car.
The smoothness of the ride was a major focus in this hull design, I'm glad to see that it is working well too.

This boat could benefit from a stepped chine but that would seriously complicate the building, the sprayrail is fine.

One question for the builder: did you put the console where we show it? It looks a little further aft. Maybe to compensate for the big nice baitwell?

[fallguy1000]

Chine flats can dry out the ride, increase top speed, but getting them right requires experimentation and the wilingness to video their performance and even to modify, perhaps multiple times.

Easy in aluminum, but on a s&g ply hull; errors in design are not easy to adjust.

They have to be done with some precision, so something less perfect that still performs is easier to design. Aka, spray rails.

But, I would tend to believe a 3" flat or reverse chine possible. Would it eliminate spray rails? Not sure. But I do like the question and am curious what Jacques says.

[TomW1]

Johnston a Australian/NZ builder did a beautiful set of chine flats on his C17 several years ago. I will try to look and see if I can find his build as he documented what he did very well.

Tom

[Johnston]

I now read he has said “stepped chine”.... so am confused whether this is the same as chine flats. I googled it and those are the slits that run down the sides of some (fast) planning boats...

[BB Sig]

I'd imagine two 40's would not have enough power to worry about a stepped chine. Use spray rails to keep dry.

[OneWayTraffic]

I now read he has said “stepped chine”.... so am confused whether this is the same as chine flats. I googled it and those are the slits that run down the sides of some (fast) planning boats...

Think he means chine flats*. Not all marine terms are precise. You can make them after the structural glassing by screwing a dam to the chine and filling the gap with an epoxy/milled glass/cabosil putty. Mix it just runny enough to lay flat. I've done that with my C17, and am happy with how it's turned out.

If thinking twin 40's I'd step up to 50s or 60s. No weight penalty, and you might be able to semi plane on a single engine.

In his post viewtopic.php?f=2&t=63623
It should be pretty clear that he's using the word chine step to refer to a built in spray rail or chine flat.

[fallguy1000]

I now read he has said “stepped chine”.... so am confused whether this is the same as chine flats. I googled it and those are the slits that run down the sides of some (fast) planning boats...

Think he means chine flats*. Not all marine terms are precise. You can make them after the structural glassing by screwing a dam to the chine and filling the gap with an epoxy/milled glass/cabosil putty. Mix it just runny enough to lay flat. I've done that with my C17, and am happy with how it's turned out.

If thinking twin 40's I'd step up to 50s or 60s. No weight penalty, and you might be able to semi plane on a single engine.

In his post viewtopic.php?f=2&t=63623
It should be pretty clear that he's using the word chine step to refer to a built in spray rail or chine flat.

A great tip if sized properly.

[TomW1]

Here is an excellent set of chines on an OB15, I believe. https://www.community.boatbuildercentra ... fullsize=1

Tom

[Johnston]

I was doing more googling on “stitch and glue Chine flats” and I see the Tolman boats come up a lot with them going from “standard” to an improved version with chine flats. I understand there are big differences in the design process but does the Tolman method carry any merrit in construction over this other way of doing them?

I am interested to note how much real difference they might make.

My assumption is if it was really a lot the designer would have incorporated them?

Could one achieve the same with a very wide spray rail...