Is a non-weld repair of pontoon hole and dent possible?

[carlazzomark]

I have a 2 1/2" x 1" hole in the middle of a 10" x 5" dent at the bottom of a pontoon. I live in an area of Italy where a mobile aluminum welder does not exist. Is there a way for me to repair the hole and dent using non-weld methods? Pic attached. Pic measurements show centimeters. Thanks.

 

[fhhuber]

Temporary... you can epoxy/fiberglass patch it. But it will be a mess to clean that off to get it fixed correctly. Eventually this type patch will start popping off of the aluminum and leak.

There is also a rod which can work using a propane torch and a patch of aluminum. I have some of the product but don't know if it would be easily available where you are.
https://www.youtube.com/watch?v=fIQ32OHvXP4
It works very well but you have to follow the directions EXACTLY. Using the wrong brush to clean the aluminum will make it fail.

 

[Tnstratofam]

What about a patch using 3m 5200 and riveted with closed end blind rivets? Make the patch 1to 2 inches larger all the way around then butter it with the 5200 and rivet over the hole. Perhaps do the same with the dent. Make the patch out of the same thickness aluminum as the pontoon.

 

[funk6294]

It looks like there might be two holes there. I suppose as stated before a temporary patch could be made with a piece of aluminum, some 5200 and use blind rivets. To do it once and do it right I would get it welded. I know you said there were no mobile welders in the area. Do you have a trailer you can use to take it to a welder?

 

[carlazzomark]

What about a patch using 3m 5200 and riveted with closed end blind rivets? Make the patch 1to 2 inches larger all the way around then butter it with the 5200 and rivet over the hole. Perhaps do the same with the dent. Make the patch out of the same thickness aluminum as the pontoon.

This is something I might try. Thanks.

 

[carlazzomark]

It looks like there might be two holes there. I suppose as stated before a temporary patch could be made with a piece of aluminum, some 5200 and use blind rivets. To do it once and do it right I would get it welded. I know you said there were no mobile welders in the area. Do you have a trailer you can use to take it to a welder?

I don't have a trailer.

 

[carlazzomark]

Temporary... you can epoxy/fiberglass patch it. But it will be a mess to clean that off to get it fixed correctly. Eventually this type patch will start popping off of the aluminum and leak.

There is also a rod which can work using a propane torch and a patch of aluminum. I have some of the product but don't know if it would be easily available where you are.
https://www.youtube.com/watch?v=fIQ32OHvXP4
It works very well but you have to follow the directions EXACTLY. Using the wrong brush to clean the aluminum will make it fail.

Thanks. I might try this in conjunction with putting a plate over everything, per Funk2694.

 

[Scott Danforth]

I would get it welded. I would also look to see what pierced the pontoon log and prevent it from happening again.

 

[HotTommy]

Carlazzomark,
If patching is your only option, here's how I would try it. I'll start with a picture representing the hole, an inside patch and and outside patch. They will be used along with the sealant mentioned above to form a sandwich patch over the hole.

As shown, the patches should be oval shaped with the width (the narrowest dimension) of the patch only sligthly smaller than the length (the longest dimension) of the hole. That should allow you to slide the inside patch through the hole when the time comes and rotate it so it overlaps the entire hole. Here are the steps as I envision them.

1. Cut two identical patches out of aluminum at least 4mm thick.
2. Lay one patch over the hole and mark its outline to see when it is centered and how much overlap there is.
3. Mark one patch for the location of holes to be drilled about 25mm apart around the circumference of the patch in the center of the overlap area.
4. Locate enough aluminum rivet nuts and bolts to fill the holes in the inside plate. They should be sized for bolts about 5-7mm in diameter and about 25mm long. Get three extra bolts about 60mm long.
5. Clamp both plates together and drill the holes marked in step 3 in a size just large enough for the bolts you will use with the rivet nuts.
6. Enlarge the holes on the inside plate to the size needed to install the rivet nuts.
7. Install the rivet nuts on the inside plate.
8. Place the outside patch over the hole and mark the location of the holes on the skin of the pontoon. Drill holes as marked in the size for the bolts.
9. Using strong duct tape, make a handle in the center of the outside facing side of the inside patch. You will use it to position the patch when it is inside the pontoon.
10. Flatten the skin of the pontoon around the hole so the patches can fit snuggly.
11. Prepare three pins (i.e., headless bolts) in the same size as the bolts you will use.
12. Generously lather the outside facing side of the inside patch with sealant, slide the patch inside the hole and manuever it into place using the handle.
13. Align the hole in the skin with the holes in the inside patch using the three pins spaced evenly around the hole.
14. Relying on the sealant and the pins to hold the inside patch, carefully remove enough of the handle to clear installation of the outside patch.
15. Carefully slide the outside patch over the three pins.
16. Insert the three extra long bolts through the outside patch, skin and into the rivet nuts. Screw them until they securely hold the inside patch.
17. Remove the pins and slide the outside patch away from the skin enough to apply sealant.
18. Apply a generous amount of sealant to the overlap area between the skin and the outer patch.
19. Slide the patch onto the sealant and skin.
20. Insert the bolts through the outside patch, skin and inside patch.
21. When all the bolts are started, remove the three extra long bolts and replace with regular bolts.
22. Tighten the bolts evenly and in stages to avoid warping the metal.
23. Let it cure.

 

[fhhuber]

Sandwich patch would assume decent access to get at the inside of the pontoon. this is not always possible.

 

[Reel Kahuna]

Sandwich patch would assume decent access to get at the inside of the pontoon. this is not always possible.

My thoughts exactly.

 

[Tnstratofam]

I think the way hottommy describes inserting the inside patch in through the existing hole and then temporarily holding it in place aleviattes the need for access to the inside of the pontoon. Although it is a little tricky I think it is quite doable, and a stronger more permanent repair than the outside only patch I described.

I'm wondering if you couldn't place the inside patch in place and let the sealant cure, then apply the outside patch making it a little easier of an install. Although it would take a little more time. Especially if you have predrilled the patches and the holes making alignment easier.

 

[HotTommy]

I think the way hottommy describes inserting the inside patch in through the existing hole and then temporarily holding it in place aleviattes the need for access to the inside of the pontoon. Although it is a little tricky I think it is quite doable, and a stronger more permanent repair than the outside only patch I described.

I'm wondering if you couldn't place the inside patch in place and let the sealant cure, then apply the outside patch making it a little easier of an install. Although it would take a little more time. Especially if you have predrilled the patches and the holes making alignment easier.

My concern with letting the sealant cure before installing the outside patch is that I wouldn't trust sheet metal screws to hold things together, and threaded bolts might have a hard time cutting through the cured sealant to engage the rivet nuts in the inside patch. Inserting the bolts through the uncured sealant will also allow the sealant to better seal the bolt holes.

 

[Tnstratofam]

That makes sense. Letting the sealnt cure with both patches in place as well as the bolts and screws would allow for the sealant to settle in and be more water tight.

 

[carlazzomark]

Carlazzomark,
If patching is your only option, here's how I would try it. I'll start with a picture representing the hole, an inside patch and and outside patch. They will be used along with the sealant mentioned above to form a sandwich patch over the hole.

As shown, the patches should be oval shaped with the width (the narrowest dimension) of the patch only sligthly smaller than the length (the longest dimension) of the hole. That should allow you to slide the inside patch through the hole when the time comes and rotate it so it overlaps the entire hole. Here are the steps as I envision them.

1. Cut two identical patches out of aluminum at least 4mm thick.
2. Lay one patch over the hole and mark its outline to see when it is centered and how much overlap there is.
3. Mark one patch for the location of holes to be drilled about 25mm apart around the circumference of the patch in the center of the overlap area.
4. Locate enough aluminum rivet nuts and bolts to fill the holes in the inside plate. They should be sized for bolts about 5-7mm in diameter and about 25mm long. Get three extra bolts about 60mm long.
5. Clamp both plates together and drill the holes marked in step 3 in a size just large enough for the bolts you will use with the rivet nuts.
6. Enlarge the holes on the inside plate to the size needed to install the rivet nuts.
7. Install the rivet nuts on the inside plate.
8. Place the outside patch over the hole and mark the location of the holes on the skin of the pontoon. Drill holes as marked in the size for the bolts.
9. Using strong duct tape, make a handle in the center of the outside facing side of the inside patch. You will use it to position the patch when it is inside the pontoon.
10. Flatten the skin of the pontoon around the hole so the patches can fit snuggly.
11. Prepare three pins (i.e., headless bolts) in the same size as the bolts you will use.
12. Generously lather the outside facing side of the inside patch with sealant, slide the patch inside the hole and manuever it into place using the handle.
13. Align the hole in the skin with the holes in the inside patch using the three pins spaced evenly around the hole.
14. Relying on the sealant and the pins to hold the inside patch, carefully remove enough of the handle to clear installation of the outside patch.
15. Carefully slide the outside patch over the three pins.
16. Insert the three extra long bolts through the outside patch, skin and into the rivet nuts. Screw them until they securely hold the inside patch.
17. Remove the pins and slide the outside patch away from the skin enough to apply sealant.
18. Apply a generous amount of sealant to the overlap area between the skin and the outer patch.
19. Slide the patch onto the sealant and skin.
20. Insert the bolts through the outside patch, skin and inside patch.
21. When all the bolts are started, remove the three extra long bolts and replace with regular bolts.
22. Tighten the bolts evenly and in stages to avoid warping the metal.
23. Let it cure.

Do I need to pull the dent out first? And if so, what is the best way to do this?

 

[HotTommy]

Your initial post described a dent and and hole. My suggestion was for the hole. If the dent has not pierced the skin so it leaks, I think I'd leave it alone for now. If it has pierced the skin, you would have to open a hole large enough for a sandwich patch to use that method. .... If you're asking about the bent metal around the larger hole, I can envision two approaches. First, consider cutting away any sections of metal that are not secure enough to hold the patches. Second, either slip the head of a hammer inside the hole to tap the metal back out flush using the hammer and dolly method, or use something like Vicegrip pliers to grab the metal and carefully bend it back into position. .. Note that aluminum is prone to weakening when it is bent back and forth. I wouldn't bend it any more than necessary to get a decent fit with the patches. ..... If the metal for the patches is thick enough, you may be able to push the bent skin back in place when you tigthen down the patches.

 

[bruceb58]

I don't see how you can fix that properly without welding. Anything else you do is going to be temporary and you will risk sinking that log when the patch fails.

 

[glust]

If you really like the boat and are intending to keep it, I would bite the bullet and rent a trailer and take it to an experienced welder. In the end, any repair short of welding it going to leak. That hole is large enough and in a bad enough place that you risk catastrophic failure while under way. Sorry about your predicament. Good luck

 

[gm280]

That gashing hole is certainly calling for a weld repair. I would clean the area very well and even try to pull the folded aluminum back out to offer better surface area for the welder to work with. But it certainly has to be seriously cleaned before it can be welded. And any effort you can do towards that end will lessen the cost as well. How were you able to get the initial picture? If you can set that option up again, you might be able to get a competent welder to come there for the repair weld. :noidea: JMHO!

 

[bruceb58]

I actually wouldn't even bother bending anything back. I would just get a square or round piece of aluminum and weld it right over the hole.