need help repairing cracks in alum. boat!

[fisher2]

hey guys, i need some advice on how to repair some cracks on the bottom of a 12' jon boat that i have. i dont have a welder, so what would be the best option as to fixing the cracks?  they are about 2" in length.

[Catt]

I personally would not trust anything but welding; regardless what you decide be sure to have the cracks stop drilled.  

[FishingBuds]

I personally would not trust anything but welding; regardless what you decide be sure to have the cracks stop drilled.

X 2

[MA1232]

You can use something like this ... http://www.marineengine.com/products/accessory.php?in=1788020

I used a gav version of this from Homedepot for my stream heating pipe and it is still holding after 3 yrs.  

members here can help you out more if you have picture of the hold.

[92 5 oh]

i talked to a welding shop down the street and they sell an Aladin 3 in 1 rod that you braze.  it uses mapp gas and it's sold usually by the pound and is roughly $20.  the guy told me it would be more than enough for a jon boat, it has a tesil strength of 40,000 psi (depending what kind you get). i have a small hole from a rivet i'm going to fill in with it and see how it works.  mines only a whole though, not a crack.  the aladin rod is similar to this stuff called HTS2000.  try a google search on it, they've got a neat video on their site about how to use and how strong it is.  i think the HTS is stronger than the 3 in 1 rod though...

or you could probably take your boat to a local welder..

[Team_Dougherty]

First choice someone who know how to weld thin aluminum.

second choice. http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?_DARGS=/cabelas/en/common/catalog/item-link.jsp_A&_DAV=SEARCH-cat21324&id=0001390010655a&navCount=2&podId=0001390&parentId=cat21324&masterpathid=&navAction=push&catalogCode=IJ&rid=&parentType=index&indexId=cat21324&hasJS=true

[fisher2]

ok, thanks for yalls help

[Low_Budget_Hooker]

I messed with alum epoxy for a few months and then Matt 5.0 just welded it for me.

It's Bulletproof now.

[jhoffman]

Im going to advise against the brazing rods unless you have an oxy acetylene torch. Those guys do those demos at sports shows on thin aluminum like pop cans. I bought some, tried it on my boat.... a mapp gas torch isnt hot enough to heat the boat to the point it will bond. And the hole I had was very small. Dont waste the money, you WILL regret it.

[Zeta]

Im going to advise against the brazing rods unless you have an oxy acetylene torch. .... a mapp gas torch isnt hot enough to heat the boat to the point it will bond. And the hole I had was very small. Dont waste the money, you WILL regret it.

I'm gonna disagree with this because I used

the brazing rods and mapp gas torch on a

pinpoint sized hole in my grumman and it bonded

perfectly.  

[=Matt 5.0=]

I messed with alum epoxy for a few months and then Matt 5.0 just welded it for me.

It's Bulletproof now.

[jhoffman]

I'm gonna disagree with this because I used

the brazing rods and mapp gas torch on a

pinpoint sized hole in my grumman and it bonded

perfectly.  

Pin point size hole... MAYBE ok... but drill out a rivet and try it, hes talking about a CRACK!

I cleaned the surface with a grinder, preped it with thinner and held the torch to it for about 5 minutes, no go padro.

[=Matt 5.0=]

I'm gonna disagree with this because I used

the brazing rods and mapp gas torch on a

pinpoint sized hole in my grumman and it bonded

perfectly.

Pin point size hole... MAYBE ok... but drill out a rivet and try it, hes talking about a CRACK!

I cleaned the surface with a grinder, preped it with thinner and held the torch to it for about 5 minutes, no go padro.

Never a good idea to prep AL with an abrasive wheel. Especially if it has been used previously on steel. You will embed steel particles into the AL making it very hard to work with.

My methods are as follows:

1. Prep with a stainless steel brush used for Aluminum Only

2. Wipe down area to be welded with acetone

3. Wipe down AL rod with acetone (you'll be amazed how dirty it can be)

Hope this helps. Alloys are a totally different world than steel.

[Zeta]

Pin point size hole... MAYBE ok... but drill out a rivet and try it, hes talking about a CRACK!

I cleaned the surface with a grinder, preped it with thinner and held the torch to it for about 5 minutes, no go padro.

Crack, hole, whatever the brazing rods do work

and they work very well.

From what you've described, it sounds like

you didn't prep it per the instructions.

Like Matt said, you have to scrub down the surface

and the rod with a stainless steel brush

for aluminum (Brush came in my kit).

The instructions in the kit I have

clearly pointed out that if you didn't use the

special ss brush, the rods wouldn't adhere.

I will be using this same kit on another hole

that's 1/4" in diameter and I have no worries

that the stuff works as advertised when done

the right way.  I'd recommend it to anyone who

wants to fix a leak on their boat on the cheap.  

[jhoffman]

Ill try your methods and I hope you are correct but it was CLEAN and no, the grinder never touched steel. Ive seen how its done with a brush. That wasnt enough so I went the other route. The only thing I didnt do was clean the rod. Like I said.... I hope youre right!

[Zeta]

For anyone else using the brazing rods, you MUST use

a stainless steel brush for the aluminum boat

and on the rods.

Just a regular wire brush will not do.

I followed the instructions on the durafix website

to a T and it worked exactly as they claimed.

Hope this helps.    

[jhoffman]

For anyone else using the brazing rods, you MUST use

a stainless steel brush for the aluminum boat

and on the rods.

Just a regular wire brush will not do.

I followed the instructions on the durafix website

to a T and it worked exactly as they claimed.

Hope this helps.    

I have a feeling these rods arent made by the same company. I went out and tried it again. With the brush and it worked fairly well. Im going to give it a try vertical tomorrow and then grind it off before i make my final decision.

I bought them at a sportsman show.