Bent deflector fin

[ronward]

Hello, first time here. I've been over at Johnson/Evinrude forum a lot. Going this weekend to pick up my first ever pontoon. Been looking here and found a lot of great insight into pontoons. I'd like to know how difficult it is to straighten a bent deflector fin and what's the best technique, the end away from the bow is almost touching the toon. Thanks for any help

 

[gm280]

ronward, if you could post a picture of your bent fin/deflector, we could provide some suggestions and ideas. Usually bent aluminum can be straightened out with a little hammering and some finesse. But not seeing what you are dealing with, that is only a wild guess. Pop up a couple pictures and let us see your problem. JMHO

 

[ahicks]

Some fins are just butt welded to the alum. tube. Others fins have a flange bent first, and that's welded to the tube. With both, it depends on how many times it's already been straightened. Docks can play hell on the spray deflectors/fins, bending them regularly if you aren't careful. After several "straightenings" a butt weld is likely starting to fatigue and crack. Straightened often enough the weld will break. Fins with flanges can usually handle more abuse, but they too will fail eventually.

My point to all that is straightening is usually done while holding your breath and crossing your fingers so nothing cracks (further) or breaks off. I don't think how or what you use to straighten, or how careful you are you stand a good chance of needing a welder when done.

Hammer marks show forever on alum. I would avoid the use of anything but a plastic, rubber or wooden mallet if you must.

 

[ronward]

I'll try posting a pic. In the meantime would heat help or is just a matter of finesse with a mallet?

 

[ronward]

Hope the pics worked.

 

[ronward]

Another pic

 

[ahicks]

I'm not a metalurgist, or even a welder, but my feeling is heat would not help.

Rather than beating it down. I would try to figure out a way to use some leverage and bend it a little at a time by hand. For instance, if you had a 6' length of 2x4, and placed one end under the fin right near the weld, then clamped the bent up section of fin to the 2x4, you would have a LOT of leverage on it. Bending it down into place should be pretty easy - without beating the hell out of it.

 

[ronward]

Good idea. This boat will not be run over about maybe 10mph because I have a 7 year old daughter that, while she loves being out on a boat, is not comfortable with any real speed. Will this fin be much of an issue in this case? She is only comfortable with what a pontoon is for... Slow cruising lol

 

[ronward]

Even in my 16' center console v-hull she says "OK daddy that's fast enough" before I ever get close to planning.

 

[clemsonfor]

Haha.

 

[clemsonfor]

At 10 mph you may not make enough speed to deflect any water unless heavily loaded

 

[clemsonfor]

My 3 year old pegs the throttle and tried to get it to go faster!

 

[ahicks]

The boat hit something (like a dock) to bend up like that. Water wouldn't do that...

 

[ronward]

I know that much ahicks. I've not even seen the boat yet...it's free I know it hit a dock hard, but what I need to know is how hard is it to fix without breaking the welds at the toon

 

[Cat nip]

I just did this to the spray fins on the sides of the transom and the only way I was able to bend them back and get them straight was to use a scissor jack from my car with about 3ft of wood on the top and the same on the bottom and just go slow and keep moving it back and forth to make sure everything was even and dont go for broke and try to get all moved at once. Mine turned out really good and it was 1/8" aluminum. The scissor jack was the only thing I could find to fit in the space under the transom and prying on it was giving me some undesirable results.

 

[ronward]

Thanks for the tips guys. I'll be sure and post results to maybe help someone else.

 

[Scott Danforth]

grab it with both hands and bend it back

or take a 3' long section of 2x4 and cut a 3" slot in the end and use it to work the metal back.

 

[muddstopper]

The problem with bending aluminum is it has a tendency to crack. I would suggest using a weed burner torch to preheat to around 250-300 degrees f and using some sort of pry bar, the 2x4 with a slot is a good suggestion, to bend back in place. Dont need the metal red or white hot, use a infared thermometer so as to not over heat. Let the metal cool naturally when finished, using water to cool will temper the aluminum and isnt necessary or desirable.

 

[ronward]

Good idea with the slotted 2x4. Going this morning to get the boat, I'll post better pics

 

[glust]

When straightening clutch and brake levers on dirtbikes, which are also aluminum, I always had luck heating them first. If you try to bend them back without heat, they break. If that were my boat, I'd heat it with a propane torch (blue bottle) and slowly bend it back. if it breaks then you had to get it re-welded anyway.. Good luck