Installing lifting strakes

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Slow Motion
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Installing lifting strakes

#1 Post by Slow Motion » Mon Jul 31, 2017 5:12 am

New member to group, Thanks for having me!
Has anyone installed lifting strakes and have pictures of where they attach?
I want to find out if i need to modify trailer to accommodate placement or if they are not necessarily need to be level with bottom of pontoons. I have ordered 5"x 5"x 1/8" aluminum angle but would like to see what works best.
Thanks

Slow Motion

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teecro
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Re: Installing lifting strakes

#2 Post by teecro » Mon Jul 31, 2017 5:20 am

i don't have pics but our tritoon has them on the inside of the outside tubes only, some boats may have more but that's how our's is set up. they are set up on the sides far enough so that our trailer support boards do not make contact, so no they are nowhere near the pontoon bottom.
T CRO
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Bamaman
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Re: Installing lifting strakes

#3 Post by Bamaman » Mon Jul 31, 2017 7:38 am

Lifting strakes have had substantial manufacturer engineering time put into them. It's not like you just weld some aluminum angle to the toons.

It also takes a better than average welder to keep from burning through the thin aluminum used in toons.

I'd suggest you inquire if the manufacturer of your boat sells their strakes through dealer parts departments. At a minimum, I'd try to find your exact boat with strakes and copy the angles, lengths and materials.
'12 Bennington 24' SSLX Yamaha 150

Slow Motion
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Re: Installing lifting strakes

#4 Post by Slow Motion » Mon Jul 31, 2017 7:44 am

My boat is a 1997 Crest 25', dealer changed hands in 2000 and does not have any information. I do however have a better than average welder doing the work.
I have been researching for weeks and each setup differs from the next but I do know adding strakes is what I need for my twin tube to get on plane with my new 150.

JLester273
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Re: Installing lifting strakes

#5 Post by JLester273 » Mon Jul 31, 2017 8:51 am

I think the lifting strakes are pretty simple devices really. Every company probably says they have researched and developed the perfect strake design...

But just go look at how newer boats are setup. All about the same spot but all different lengths. I would think if your installing them the biggest issue is getting them straight and making sure they are welded correctly.

If I were to do it to my boat it would be inside the logs only, If you have a center log I'd research more I guess because I think that might change things. I haven't paid attention to it much as I don't have a center log. I think full length makes the most sense. But have seen different designs there too.

Good welder and pressure test after it is all done.


I've looked at used and scratch and dent logs and seen different styles. I'm thinking of eventually replacing mine so that is where I have seen them. Might help looking for them and seeing how most are done yourself and deciding.
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rbtnt
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Re: Installing lifting strakes

#6 Post by rbtnt » Mon Jul 31, 2017 12:19 pm

Back then, Crest had an HPT option which included lifting strakes on inside and out, thicker aluminum toons at .100 and they are 27" diameter toons. They only had twin toon pontoons back then. The strakes were 2.25" X 2.25". The lower edge of the strake is 8" from the bottom centerline of the toon. The strakes are tacked on with about a 2" weld every 12" - 15".

I believe they might of had more cross members for better support as Crest toons seem to twist a little when going over waves when running on the strakes.
Last edited by rbtnt on Mon Jul 31, 2017 6:03 pm, edited 1 time in total.
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rancherlee
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Re: Installing lifting strakes

#7 Post by rancherlee » Mon Jul 31, 2017 5:07 pm

It all depends on your use. If your just looking for straight line speed/minimum plane speed then I would install them with a bit of a negative angle to "hold" the water. Positive angle will let some water escape and provide a better ride and handling while giving up some speed. The Positive angle will probably be less stressful on the tube also if you have only .080 thick tubes. If you are installing them on the outside also it's common for manufacture to leave the last 2-3 feet without a strake to aid in turning. I have tubes from 2 brands under mine and both have about 3" of weld every 2' on the strakes. I added another 3" of weld inbetween the factory welds since I like overkill! It took a bit of testing with scrap material but I really dialed in the setting on my Hobart Handler 190 spoolgun to weld nice strong beads without burning through.
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Slow Motion
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Re: Installing lifting strakes

#8 Post by Slow Motion » Tue Aug 01, 2017 6:36 am

Thanks very helpful!!

WI-RiverRat
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Re: Installing lifting strakes

#9 Post by WI-RiverRat » Fri Aug 25, 2017 11:07 am

I've also had stray thoughts about adding strakes...
Have not yet spent any time investigating design specifics.

Can you define "Positive" vs. "Negative" angle?

Which do you think would be the most bang for the buck on a twin tube 22' Bennington w/ 115 Merc 4 Stroke: Adding a 3/4 middle toon (possibly with strakes) or simply adding strakes (inside & out) on the existing pontoons?

Thanks in advance for any and all opinions and advice!
Tony
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Bamaman
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Re: Installing lifting strakes

#10 Post by Bamaman » Fri Aug 25, 2017 3:24 pm

[quote="WI-RiverRat" :devillol

Which do you think would be the most bang for the buck on a twin tube 22' Bennington w/ 115 Merc 4 Stroke: Adding a 3/4 middle toon (possibly with strakes) or simply adding strakes (inside & out) on the existing pontoons?
Tony[/quote]

If your Bennie is relatively late model, go with the OEM Express center tube with strakes. Your dealer can order one, and it is a simple bolt on. You would also want underpinning If it doesn't already skinned.
'12 Bennington 24' SSLX Yamaha 150

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Jake_Daddy
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Re: Installing lifting strakes

#11 Post by Jake_Daddy » Mon Aug 28, 2017 5:27 am

I am going to have to agree with JLester on this one about everyone "saying" they have engineered the best possible lifting strakes! There are a lot of boat manufactures around here, not pontoons though, and I have had the pleasure working with many of them on different projects. You would be amazed at the lack of thought that is put into some of these boats and I am not talking about just one company either. I have seen companies that know a new design will be a POS but due to scheduling and pressure from dealers they put it out anyway only for a customer to get the shaft after they purchase!

End of the day your adding a planing surface to the tubes you can tweak it to get max speed at the expense of comfort or max comfort at the expense of speed which would be no strakes at all. I would say worst case after you install them is you need to drop your motor a bit beacuse the stern should lift a bit at speed.
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