Temporary prop repair with JB weld?

Just got home from fishing the ohio river, some backwaters of the ohio river, and some creeks. We have had a lot of rain and there was a decent amount of debris in the water that cleared up for the most part by around noon or so. Anyways, when I pulled the boat out of the water and tilted the motor up one blade on the prop had this crack in it:

As you can see the prop was already in pretty bad shape with lots of dings and chips. The bent out edge on that blade was already like that. I was already thinking about getting a new one and using this one for backup sometime soon down the road. I didn't hit anything big really unless that one blade caught something maybe? The only decent size log I hit was at idle when i was going into some backwaters from the river; walls of debris form at all these areas and it was floating just an inch or two below the water, covered up by a bunch on small sticks and stuff floating just over it. I didnt think it hit the prop, actually I was basically sure of it at the time, it felt like the hull pushed it to the side, but maybe it did hit it. I couldn't see any marks on the skeg that looked fresh or different.

So Memorial Day is coming up and I have the day off work so I would like to use the boat has anyone ever tried doing a repair on an aluminum prop with JB Weld? I figure it can't hurt to give it a shot? I figure it might last until the next time I hit something, which will happen as much as my boat sees the river and creeks.

I figure this thread will stir up some stuff so let it go lets here what you think!

I think JB Weld is strong but it's not that strong and a big glob of it will also throw your prop even more out of balance than it already is.

Run it very much like that and you will be replacing seals (at the very least).

what seals are you talking about? you think it could damage the lower unit or something? Every motor I have every owned had real dinged up props already, so I figure they must be unbalanced slightly at the minimum. Then again both were under 10hp on a ancient 14ft flat bottom steel monarch. This is on a 40hp that I GPS'd the speed at 29 miles an our in 4-6" of chop on the Ohio river between Kentucky and Indiana. So the point is that I have never had a motor this powerful or a boat this fast and it was never anything we worried about, and we have had the johnson for somewhere around 15 years probably. Looks like I will be on the under 10 hp lake on memorial day with my johnson 7.5 instead of cruising down the river like I planned... dang bad news sucks somebody tell me it should work! haha

also, that edge was bent out a lot more than that when I got it, I filed it down some, but i also filed and smoothed out edges of the other blades some, so I might be adding back some weight I removed? man I want this to work!

quackrstackr, you fish ky lake a lot right? I'm jealous, I am planning a camping/fishing trip to land between the lakes towards the end of the summer, I can't wait.

sorry, JB is def. not designed for that type of rpm/pressure. is there someone in you area that reconditions props? or that could do a weld and balance to your existing prop? with jb you could end up losing that piece of prop if it separated, and who knows which way it may go! :shock:

wolfmjc said:

sorry, JB is def. not designed for that type of rpm/pressure. is there someone in you area that reconditions props? or that could do a weld and balance to your existing prop? with jb you could end up losing that piece of prop if it separated, and who knows which way it may go! :shock:

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I figure I would be better off just buying a new one, I've priced them a little under/around $100, so I figure I would spend at least half or three quarters that having it repaired right so I figure going new is the best bet. And I don't know of and google is not coming up with any prop shops around me.

Also, I ran WOT for over 10 miles down the river back to area we launched at after the only time I think I could have possibly hit something.

I'm not sure what it would cost to refab the existing prop but may be a good backup? still bites to tear one up....sorry...

sturdi87 said:

quackrstackr, you fish ky lake a lot right? I'm jealous, I am planning a camping/fishing trip to land between the lakes towards the end of the summer, I can't wait.

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Yeah. I live 12 miles from KY Lake and can be in LBL in about 20 minutes.

An out of balance prop will ruin your prop shaft seal and you will start getting water in your l/u.

That may just be a stress fracture from a previous hit that got aggravated today and opened up on your long run to and from where you were at. A 10 mile run is more than long enough to start slinging one apart that had a crack in a blade.

Happens to bass boats quite a bit. They will be going along in 50 feet of water and suddenly one blade just lets loose for no apparent reason. Usually related to damage earlier on that make unnoticeable cracks. Me on the other hand, I can show you exactly where the rock mine hit is. :roll:

sturdi87 said:

I figure it can't hurt to give it a shot?

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What if it breaks loose and puts hole in the hull? How much is the hull worth compared to a new prop? What if it destroys the seals, which then destroys the bearings causing the lower unit to lock up twisting the drive shaft in two and bends the connecting rods? How much is a prop compared to new motor?