View Full Version : Aluminum boat repair

February 16, 2005, 16:36
I've brazed and welded just about every common metal known but I am now in need of an aluminum patch job on the bow of my boat (something I've never done). Some person :confused: decided to crank the winch down super tight and it cracked the weld where the bow hook is. More like a large gaping crack 1/4" across and 5 inches long (rip).

In doing so, they also denting the bottom of the boat where the guide roller rests (yeah, they cranked the crap out of that winch). The dent is no big deal and can be hammered out easily but the crack/rip has me wondering if I can repair this myself.
I've seen the repair rods demonstrated at gunshows where you heat the surface to be repaired and quickly rub the rod across the damaged area until the rod flows. I can close the crack on my boat to where the edges touch but will this type of repair be tough enough to withstand the rigors of this area of the boat?

Should I just find somebody to stitch this thing up? Expense?

Looks really do not matter on the boat but function does.

February 16, 2005, 16:45
The area in question. I will take a close-up pic later of the actual crack.

February 16, 2005, 20:17
Consider the special rods and s.s. brush as sold at some shows an aluminum equivalent to medium hard solder. BTDT !
I would recommend someone TiG it properly for you. Mebbe even put a patch over the repair and stitch it on good.


Jon Frum
February 16, 2005, 20:22
I hauled my pontoon boat to a welding shop and had them do it.

February 16, 2005, 21:04
Originally posted by WILD BILL
I hauled my pontoon boat to a welding shop and had them do it.

Ditto on that. Take it to a pro and have it TIG'd

February 17, 2005, 00:32
could you pop rivet a patch over the tear then weld w/ the rod you mentioned.

February 17, 2005, 01:40
I used the aluminum brazing rods you talk about Faltitude to repair some screw holes in my aluminum boat. It held up and sealed the holes as well. Note, they were just screw holes from a previous mounting experiment, not a structual sensitive area.

Tig is best!

February 17, 2005, 02:30
Here ya go, Tude! :wink:

From McMaster Carr's website:

Aluminum Soldering Flux
Use this paste flux with any tin/lead solder to solder aluminum and aluminum alloys. Also for use with copper, chrome, and brass. Meets DOD 1866.

4-oz. Jar 7696A2 $7.17

1-lb. Can 7696A1 23.07


Aluminum Solder
For soldering aluminum to itself and to its alloys.
Aluminum Solder Rod— Zinc/aluminum alloy solders aluminum without the use of flux. It also solders copper and stainless steel when used with external fluxes. Melting temperature is 710° to 725° F.
Aluminum Solder Bars and Wire— Tin/zinc alloy requires the use of flux, see 7696A series above. Melting temperature is 390° to 650° F.

2-lb., 0.125" x 18" Rod† 7664A4 $31.20

3.4-oz. Bar• 7664A21 7.77

0.85-lb. Bar 7664A11 30.27

1-lb., 0.125" Diameter Wire 7664A31 27.25

† Approximately 36 rods. • Weight is approximate.

McMaster Carr (http://www.mcmaster.com/)

Search for "aluminum solder"


February 17, 2005, 08:07
Keep all the weight to the rear, the motor tilted some, the throttle cranked up and don't sweat it...... :tongue:

February 17, 2005, 08:22
Long shot, Jeff, If ya have a trip anywhere near Katy, TX (west of Houston about 10 miles) I'll get it fixed for ya at our shop. Gratis. Take about an hour. Counting breeze shooting time.

The guys are right. Needs Tig'ed with a .100 backup plate. Won't happen again.

IF and ONLY IF you are the kind of cobbler I am, you could take two .100 plates and sandwich that section of the hull with the winch eye centered. Bolt it around the perimeter of the patches with SS machine screws,washers,nuts and sealed with good GE silicone. No source for .100 alum ? WRONG. Measure it and I'll send a coupla pieces.


PS looks like you'll need to cut an access hole in the bow seat to get to the back side. Measure that and we'll send a plate for that too!

February 17, 2005, 08:24
A fast and a fairly good repair can be done with a caulking called Vulkem 116
it is a polyurethane. It sets up hard and will stick to metal (any) like crazy.

I patched bullets holes in my canoe by cutting a piece of aluminum then applied this caulking to the piece of aluminum then pop rivets (closed end pop rivets)
about a 1/2" apart around the patch piece.

The holes were on the bottom of the canoe (well, some of the holes) right were
it curves. It is "sea worthy" never had a problem with it since and this is a
high stress area on the canoe.

Then again ...there are othe good suggestions stated above. Just thought I'd pass this idea along.

This area on your boat looks like it is going take lots of abuse. Dont know how well a caulking patch job would hold up against a winch/pull/stress

This thread show my boats and where I had to repair


February 17, 2005, 09:55
it's called alumaloy (spelling)

ya dont need other crap to go with it
just clean
and heat

use only a ss brush
and only a new one just for the alumaloy

February 17, 2005, 13:01
Originally posted by BIG DUKE 60
it's called alumaloy (spelling)

ya dont need other crap to go with it
just clean
and heat

use only a ss brush
and only a new one just for the alumaloy

That's the Stuff I was thinking on. Use that if you're lazy. Tig-welding is the "proper" way to go with the backing plates, but this will work.

February 17, 2005, 20:27
My Nissan truck recently had the aluminum ended A/C hose leaked all the R134A out and I cut off the propietary ends and aluminum brazed some barbed ends to attach new hose to.Works great!Tig is great, but I like doing things myself.

February 22, 2005, 20:44
Originally posted by BIG DUKE 60
it's called alumaloy (spelling)

ya dont need other crap to go with it
just clean
and heat

use only a ss brush
and only a new one just for the alumaloy
Nice stuff and a simple propane torch does it.

If I could aford a TIG unit I wouldn't be in an aluminum boat.

Do it yourselfers carry on!:biggrin: