Welding Strakes on Pontoons

[arntarchie]

Re: Welding Strakes on Pontoons

just found this, Pontoon Boat Liner by Universal Linings - YouTube

 

[richard.prince]

Re: Welding Strakes on Pontoons

just found this, Pontoon Boat Liner by Universal Linings - YouTube

Not sure how I would feel about spraying my logs with spray on bedliner

 

[MH Hawker]

Re: Welding Strakes on Pontoons

Sadly not much if any thing will stick to alum, if it did it would be in common use in salt water areas where its common for pin holes to develop.

 

[ahicks]

Re: Welding Strakes on Pontoons

Sadly not much if any thing will stick to alum, if it did it would be in common use in salt water areas where its common for pin holes to develop.

Regarding nothing sticking, what about painted alum. boats? Airplanes might be another example?

It's about careful prep! Acid wash, followed by epoxy based primer, then?

 

[arntarchie]

Re: Welding Strakes on Pontoons

Sorry for any confusion, I found the that vid by accident and thought I would share it
If you intend to fix the welds DO NOT PUT ANYTHING on the logs that would make your welder vary unhappy...
And yes we have been painting aluminum for some time.

 

[5150abf]

Re: Welding Strakes on Pontoons

Here I am, Have been really busy and got out the habit of hitting the site.

DO NOT- DO NOT use any type of epoxy if you ever what this actually fixed, welding is the only way to fix it for and once you get epoxy in the mix it will be next to impossible to weld.

You have the chine welded on then the boat started to leak, yes?

That would make it the welders problem to find and fix the leak and submersing the boat isn't going to find anything unless the tubes are aired up and then you would just be able to see approx. where they were leaking, you need a spray bottle and soap and water.

If it did start leaking after it was welded it can't be anywhere but where it was welded, if that makes sense, the weld only touches a very small bit of the tube, maybe and 1/6 to 3/16 wide and that is the only place it can leak.

In my shop I would air it up and start spraying, once you find the leak carefully drill,3/16'' bit, the weld /chine without going though, you just want to remove the weld and clear just enough room to tap it with a weld and fix it, go 1-2 drills beyond the actual hole and make certain the plugs are pulled and there is no pressure in the tube.

Also make sure it is bone dry, water is H2O, the O being oxygen and nothing is worse for a weld.

I will start checking back if you have more questions

 

[edthewrench]

Re: Welding Strakes on Pontoons

I'd locate the leak before doing anything. Do you know anyone with an auto shop? Our shop has a smoke machine used to find evap leaks in fuel systems and engine vacuum leaks. You could fill the logs with the smoke (it gets pressurized slightly) and watch to see where the smoke exits. It's a surefire way to know exactly where the leak is.

 

[Silver Eagle]

Re: Welding Strakes on Pontoons

Does anyone have pictures of lifting Strakes? Are they those wing like thing on the front of the tones one on each side.? If that's what they are I thought all pontoon boats had them.

 

[fergusmj]

Re: Welding Strakes on Pontoons

Look at this picture. Left toon does not have strakes and the right toon does. What you're talking about are the splash fins (I think). Strakes help lift the boat up out of the water to make it more like a planing hull. Kind of acting like skis.


http://www.custompontoonboatkitsetc...ontoons/.pond/liftingstrakes.JPG.w300h225.jpg

 

[Silver Eagle]

Re: Welding Strakes on Pontoons

OK Thanks. It looks like I don't have them. Does that make it harder to put a pontoon boat on a Bunk trailer.?

 

[MaPaHa]

Re: Welding Strakes on Pontoons

5150abf,

I had some leaks in them at the tube joints a few years ago when it was a twin toon and was bouncing too much on the trailer. (There are 3 joints connecting the tubes which are 5 feet each plus a final joint connecting the nose cone. 20 feet of straight tube with no inside partitions and then the nose cone. The drain plug on the rear drains everything). Most all of the old leaks were around the joints just above both ends of the axle hangers (dual axle). Once I installed the center toon with another bunk and had the toon joints fixed they never leaked anymore so I thought a couple of years later was long enough to wait to add the strakes. So they were not leaking within two seasons before the strakes were added.

The center toon was new and built with a motor transom on it so between everything, it took the stress off of the side toons while trailering. I have since beefed up the trailer with a 3" x 4" x 1/4 angle down the entire trailer and rewelded the spring hangers and fenders on. It was a factory trailer before about 10 years old but it's a hoss now. I'm convinced that most pontoon leaks come from trailering.

We have been all over it with soap and water and there are absolutely no visible welds leaking and no bubbles from inside that come out. I can hear them leaking using a listening device up to my ear in a quite shop (a piece of garden hose about 3 feet long without any fittings). As I run along the strake and get close to the some of the welds the noise picks up but it's hard to tell if it's the lower weld or upper but I know I'm in the area of a leak.

The best I can tell is the leaks are where the welds burned through the tube on the inside of the strake (in the triangle part you can't get to) but the outside part of the weld doesn't leak. My worst fear is that one or more of the tube joints broke loose from one of the old repairs but I don't know that.

I agree that submerging them will only show the general area. I figured out a way to pressurize them on the water so thats not a problem so I guess in one respect I'd like to see some bubbles because it seems like I'm chasing a ghost, but on the other hand it would probably be a waste of time.

I also agree that this should be the welding shop's problem but at this point I'm trying to look out after my interest. I just want to figure out ahead of taking it in where the problem is and know what course of action would be best before they start doing anything. I'm not one to tell a professional how to do their job, but I want to know what to listen for and if it makes sense and be helpful in a nice way. I never thought it was a good idea to complain to the cook before he cooks your hamburger.

So... if it could be reasonably determined what weld was leaking, you are saying to drill the mass of weld away but not through the tube and then go in and build it back out with a weld? Would grinding the welds down with a small cut-off tool do the same thing? Once the blown out part is seen, would you then drill through the tube where the hole is and fill back in? Drilling the holes is something I never really understood.

Maybe another way to ask it is... if there were a leak along a tube such as a split, where would you use the drill and a small bit? At the ends to keep it from running, along the split, or next to the split. I don't understand where the small holes should be on a basic repair. Once I get that picture then I'll better understand what need to happen with this problem.


edthewrench,

I like your idea about the smoke. I'm going to mark where I hear them leaking and then try the smoke and see if it agrees. I'll find someone with a smoke machine or dream up a way to get smoke in it.

I got the shop cleaned up from some winter projects and will start on this next. Will let you know what I find.

Mark

 

[5150abf]

Re: Welding Strakes on Pontoons

You use the drill to clear away the weld to repair it once you find a leak but yes, with a crack you also drill the end to stop it.

Without seeing the boat it is hard to tell where it is leaking but it has to within the width of the weld and the old repairs could have cracked but after this much time I kinda doubt they did but again without looking at it myself hard t tell.

 

[Lake Lizzard]

Re: Welding Strakes on Pontoons

The welding shop is going to weld it in one of two ways. Either with a TIG welder or a MIG welder with a spool gun. It will depend on the aluminum thickness and experience of the welder which machine they will use. In my opinion, the TIG welder is a better way to go as the welder generally will have better heat control with this method. You don't have to go to a boat shop for this. For better results, I would likely go to a welding shop where they do this type of welding all the time.

 

[MaPaHa]

Re: Welding Strakes on Pontoons

5150abf,
Lake Lizzard,

Thanks for the input. Hopefully this weekend I'll get to spend some time with it. I'm either going to try the smoke approach or get enough weight on the boat to submerse the strakes and pressurize them on the water to see the general area of the leaks. If I can isolate at least some of the leaks then they can work on those first. I need a good way to test and re-test so We'll know when their all fixed.

I hope you're right about the old repairs not leaking. If so, it sounds like they can be repaired the way you are saying because the leaks will be within reach of the welds once they're drilled away. If a tube joint is leaking at the old repairs then there's no way to get to it without cutting part of the strake out. If we have to go to that I think they should put a patch over the old welds that goes out a bit and then put the strake back on to cover it up. I hate the idea of having the strakes cut and spliced back together for looks.

If the leaks are random at various welds and not at the tube joints then that's good. If the leaks are at the old repairs at the tube joints behind the strakes then that's bad.

I'll re-post one way or the other.

Mark

 

[MaPaHa]

Re: Welding Strakes on Pontoons

Some new info,

I rechecked for leaks with a couple PSI and I can hear the leaks coming from behind the strakes in several areas. Soap solution does not work to isolate the welds that are leaking. I had to know if the old repairs at the tube joints were leaking so I drilled a 7/16 hole on the bottom side of the strake where the joint is and used a camera to look inside the strake. I did this on three joints. I squirted soap solution from the top and let it run down the joint weld and I found two of the three joints leaking where the old repairs were made. Bummer!!

I know for sure I've got a combination of strake welds and pontoon joint repair welds leaking. Without cutting a section of strake out that's large enough to get to the old joint welds there is no way to access those other than removing the strakes. The welding shop and myself have tried everything we know to isolate the leaking strake welds and nothing shows up other than listening and getting in the general area of the leak. At this point I'm thinking about removing the strakes. I took a cut-off tool and cut away one strake weld just to test the method and it took about 10 minutes to carefully cut off a 2.5" weld to where the strake severed from the toon at that spot.

?? If I took the strakes off, what would be the best repair of the tube joints before the strakes are re-installed? Would a patch be the best approach to cover the entire area of the leaking joint? Something like a 4 x 5 patch welded all the way around it and then the strake would cover it up. I don't think just welding the joint again will last.

Naturally, if the strakes come off then any leaking strake welds could be found and fixed.

How long should it take to weld the strakes back on? There are about 10 - 12 welds on the top and bottom of each strake (20-24 total per strake). Each weld is about 2.5 " long. How much would a welding shop charge if the strakes were strapped on to the toons and ready to weld.

Thanks,

Mark

 

[arntarchie]

Re: Welding Strakes on Pontoons

You payed a shop to weld on your strakes.... and not only got bad welds but they screwed up the integrity of your logs.... in my shop you pay "NOTHING".... and in 12 months when you pop another weld they fix that one also.

 

[MaPaHa]

Re: Welding Strakes on Pontoons

arntarchie,

Thanks, I need more of that attitude at this point. First and foremost I want my boat fixed right and since the previous welder (that's no longer there) messed it up I want to make sure it's fixed right this time. I've decided to cut one strake off myself because I want to know where the problem is. It will take me a couple of hours but from there if it's the way I think it will be, then they will do the other ones. The grey area is the old repairs that are underneath the strakes. If the old repairs are the major source of the leaks (which I don't think they are) then the water gets muddy as to who's responsible. The same welding shop repaired these "splits across the tube joints" a few years ago but they weren't the first ones to weld on them. They held fine for a couple of years before the strakes were added.

I talked to the shop today and the welder that's probably going to do the work said he thought the strakes needed to come off, which I agree. He would take them off, but I want to do one to see what's going on and he was OK with that. I should get it off tomorrow and repost by the end of the weekend. I'm set to take it to them a week from now.

Mark

 

[BrianMc]

Re: Welding Strakes on Pontoons

I wish you luck, MaPaHa. It's tuff repairing an old weld that's been welded up several times already. 5150abf has probably been here before,and might have better advice for you. If you hope to fix the old weld you'll have to take it down to clean aluminum. That won't be easy on thin aluminum. A patch might be the way to go.

 

[MaPaHa]

Re: Welding Strakes on Pontoons

Brian,

The patch would normally look like heck but in this case it will be covered up by the strake so it doesn't matter. I like the idea of clearing off the old welds and starting over. I'll get one off and see what else is behind it but with the camera I can see for sure where the longitudinal repair welds cross the transverse joints of the toon are leaking. I'm thinking the patch would be the way to go so it would get into some undisturbed aluminum to weld to. I can't see piling on more weld would be a long term fix. Any ideas on how far out to go on the patch would be appreciated. They should be able to re install the strakes OK and fix their messed up welds.

My strakes are the exact same as yours and I think we got them from the same place in southwest MO. Did you install yours on old pontoons like it appears in your video or were they new pontoons?
How far apart would you put the skip welds along the strake? I looked at your pictures but couldn't tell how far apart the welds are.
About how long should each weld be?
Would you line the top and bottom weld up or stagger them?

It seems to me the lifting pressure created from the strakes is transmitted to the pontoons mostly through the welds with more through the upper welds than the lower ones. It seems there is some force along the bottom unwelded surface pushing up on the bottom of the toon but not much on the unwelded upper surface. Overall it seems like the bottom edge has a consistent lift pressure while the upper edge pressure is only at the welds. I'm not sure staggering would make a difference or not. Just thinking...

Mark

 

[BrianMc]

Re: Welding Strakes on Pontoons

I'm not sure the size of patch is that important,as long as your welding on shiny clean aluminum. Maybe an inch beyond the bad spot. Just make sure there are no square corners on your patch. Make them well rounded.

I installed strakes on my old tubes. But did you notice they were sanded clean before I started? I didn't pay too much attention to the spread,2"-3" welds around 12"-18" apart. I think staggered is the way to go. The welds do take some stress on plane,but not as much as you'd think. Take mine for example. I used the bottom of the tubes with the strake locations to create approx. 70 sq. ft of planning surface,or 10,080 sq. in. At 3,200 lbs of boat that's only around .32 lbs per sq. in. on the strakes...give or take. Even if it's 3 times that it's not much pressure on the strakes. Between 4-20' strakes there is 160' of strake edge/divided by 18" between welds = 106-2 1/2" welds/or 266" of welds.

You could hang the pontoon from the shop ceiling by it's strakes. lol Now there are other forces at play. But, when you put things in perspective there fairly stout.