PG 25, July 2017, PangaRon

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Jeff
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Re: PG 25, July 2017, PangaRon

Post by Jeff »

That is a great photo!! PangaRon, would you send me a few photos of your finished Panga. Just email them to me at: jeff@boatbuildercentral.com

I will add them to our website!!! Jeff

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Re: PG 25, July 2017, PangaRon

Post by TomTom »

Very good looking boat Ron! Love the photo.

Did you ever manage to do an RPM vs Speed test on your boat? Fascinated to see how these Pangas transition from displacement to planing....

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Re: PG 25, July 2017, PangaRon

Post by jacquesmm »

About the self bailing:
there is something wrong here but I don't know what.
I first checked my calculations and with boat at level trim, it should displace 3,300 lbs before any water begins to enter the scuppers.
Is it correct that your scale puts it at 2,400 lbs and that water still gets to or above the scuppers?
Looking at the picture, your boat is sitting low, she looks much heavier. You can see where the chine immerses: she looks like she is 1 or 2,000 lbs overweight.
That does not make her a bad boat, she can still perform well.
Let's see if we can keep that water out.
If it was only 1", we could consider raising the sole with a layer of foam but 4 or 5" is a lot more .
Is that water mostly in stern? Can you draw a little sketch so that I can calculate your displacement?

Adding this to your tendency too broach in bad weather and we could have an exceedingly heavy stern.

Tell me how that water sits like: 4: above sole at MW bulkhead with the forward edge of the flood water 20" in front of that bulkhead. Those figures will give me the trim and the displacement.

The solution will almost certainly be some special scuppers, the kind we use on some sailbaots, with a ball and a shock cord but I would like to first understand why we have that problem.
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http://boatbuildercentral.com

fallguy1000
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Re: PG 25, July 2017, PangaRon

Post by fallguy1000 »

jacquesmm wrote: Mon Aug 02, 2021 4:21 pm About the self bailing:
there is something wrong here but I don't know what.
I first checked my calculations and with boat at level trim, it should displace 3,300 lbs before any water begins to enter the scuppers.
Is it correct that your scale puts it at 2,400 lbs and that water still gets to or above the scuppers?
Looking at the picture, your boat is sitting low, she looks much heavier. You can see where the chine immerses: she looks like she is 1 or 2,000 lbs overweight.
That does not make her a bad boat, she can still perform well.
Let's see if we can keep that water out.
If it was only 1", we could consider raising the sole with a layer of foam but 4 or 5" is a lot more .
Is that water mostly in stern? Can you draw a little sketch so that I can calculate your displacement?

Adding this to your tendency too broach in bad weather and we could have an exceedingly heavy stern.

Tell me how that water sits like: 4: above sole at MW bulkhead with the forward edge of the flood water 20" in front of that bulkhead. Those figures will give me the trim and the displacement.

The solution will almost certainly be some special scuppers, the kind we use on some sailbaots, with a ball and a shock cord but I would like to first understand why we have that problem.

Things like a stainless t top add to the weight, a LOT. 400#? Ron is a fisherman and a lot of downrigging gear adds up fast. I have 3 rigging balls that are 24#. My salmon fishing box is about 10#, rods are another 20# at least or more with lead. Then catch and livewell aft add up fast, say a 25 gallon well and 65 pounds of fish and you are adding 465# to loaded weight. The gear and t top could be 3" of ppi...

The thing to measure is whether the transom, if made as spec'd, is above water the right amount.

Now, I don't want to be an arse here, cuz I really luv seeing Ron's fish pics, but I have a feelin he is adding weights from midship to the stern fast.

A way to deal with this issue would be to move some static weights forward perhaps, or to put the boat on a diet.

The bottom line is the panga was not meant for lotsa fanciness like t tops and livewells and tons of gear. So Ron's critique against his use is probably ... fair.
My boat build is here -------->

viewtopic.php?f=12&t=62495

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Re: PG 25, July 2017, PangaRon

Post by TomW1 »

Ron was that an empty weight at the scales. Did you have gas or bait wells, live wells filled. Did you have any gear on boat. As another to Jaucques measure how far the scuppers set above the water line when at rest at the dock. Let him know what gear you have on board at the transom and if any tanks are filled how many gallons.

Tom
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PangaRon
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Re: PG 25, July 2017, PangaRon

Post by PangaRon »

Tom, I was on an ag scale so no water in the bait tank, no persons aboard and some 10-15 pounds of gear in the stern lockers. The 32 gallon gas tank in the bow was probably half full. Stryker aluminum T-Top was installed. Honda 90 hp weighs 300 lbs I think. I weigh 185, one mate weighs about the same.

I will measure the height and width of the standing water next time I'm out.

I have ordered the Rabud - 3" Sea Scupper, which is the Ping Ball style. I will install temporarily over the openings and report back on the effectiveness.

Thanks for the help!

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Re: PG 25, July 2017, PangaRon

Post by TomW1 »

Jacques, I would check the PPI calculation. Do to the unique design of the Panga's hull shape I would think the normal calculation may not work for them. Looking at the DE25 it has a PPi of 600lbs while you list the Panga 25 at 510lbs only 90lbs less. I would believe it might be in the 400-450lbs range, since it has 6" less beam and the sharp bow and a pinched transom. As always correct me if I am wrong.

Regards, Tom
Last edited by TomW1 on Tue Aug 03, 2021 3:49 pm, edited 2 times in total.
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

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Re: PG 25, July 2017, PangaRon

Post by TomW1 »

PangaRon wrote: Tue Aug 03, 2021 2:24 pm Tom, I was on an ag scale so no water in the bait tank, no persons aboard and some 10-15 pounds of gear in the stern lockers. The 32 gallon gas tank in the bow was probably half full. Stryker aluminum T-Top was installed. Honda 90 hp weighs 300 lbs I think. I weigh 185, one mate weighs about the same.

I will measure the height and width of the standing water next time I'm out.

I have ordered the Rabud - 3" Sea Scupper, which is the Ping Ball style. I will install temporarily over the openings and report back on the effectiveness.

Thanks for the help!
Ron the Honda specs list the 90 at 365lbs. for your future info. Jacques will do his best to figure out the problem. :D

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

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Re: PG 25, July 2017, PangaRon

Post by jacquesmm »

I will post the hydrostatics but that is not going to help with a solution.
I can not do it now, I am travelling and don't have all the software I need with me but I have a copy here in PDF and the study plans figures are correct.
Those calculations are made in ORCA and a volume is volume, whatever way it is calculated
Weight and trim seem to be the problem here.
Besides scuppers that close, I see only one other remedy, raising the sole with a thick layer of foam, glassed. Before we discuss that, I would like to know more about the trim.
Jacques Mertens - Designer
http://boatbuildercentral.com

PangaRon
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Re: PG 25, July 2017, PangaRon

Post by PangaRon »

To answer Jacques question: When I stand alone at the transom, there is 2 inches of standing water tapering to 6 feet on one side. When two people stand at the transom, there is at least 4 inches tapering to 10 feet on both sides. This is with the bait well empty. The Styker T-Top weighs 98 pounds. The Honda 90 weighs 365 pounds. The 32 gallon fuel tank is in the bow.

I temporarily installed two 3 1/2 inch Rabud ping ball scupper drains to see if this would help. These have 1 1/2" inch holes. It made the situation worse because the standing water drained out much slower when we started under way.

I'm not looking forward to rebuilding the sole and drains that run though the bilge. It will also lower my freeboard. Hopefully that is not the only solution! If so, I'll probably just keep wearing the high boots! :)

Evan Gatehouse recommended elephant trunk drains, but that seem impractical on a planing boat.

I have seen "tennis ball drains" with a pull cord on small sailboats, and am willing to give them a try, if I can locate them and make them work? I'm a little concerned about swamping!?

Please let me know if you have any other suggestions?

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