Repairing  your leaking pontoon boat hull

 

Pontoon hulls are usually made from aluminum or steel and sometimes rivet filled. The hulls are subject to corrosion or rivet leaks if made from aluminum.

If the hulls are aluminum they sometimes corrode into a white powder and become thinner and thinner. Pinholes then form through the hull.  Often too the damaged area is too thin to weld on a patch. If that is your case you epoxy paint the hulls with a special flexible, warm weather epoxy paint to fill the pits or holes in the aluminum. Fiberglass cloth can be incorporated with the epoxy paint to strengthen the weak, thin aluminum.

The epoxy paint used to for coating pontoon hulls is CM 15 (find in epoxyproducts.com marine paint catalog page (click here)). CM 15 epoxy is used because it has a long working/pot life time (necessary when working in hot summer weather), and a good bit of flex (needed for pontoon hulls). It was originally designed for gasoline storage tanks in the Gulf Coast. Three or four inch wide rolls of fiberglass cloth can be found at the same epoxyproducts.com misc products catalog page (FIBERGLASS click here). Some people paint the entire pontoon, others just from the waterline down. Note that epoxy paints are very thick, sort of like painting with honey. Epoxies are two part products - mix them in small batches because they have a short working time of perhaps 30 minutes or so (lots of things affect working time but most especially temperature). Color is ivory or black (note that CM 15 is modern replacement for coal tar epoxy).

 

If a thicker repair product is needed for dents, gaps etc, then our WET DRY 700 epoxy paste is a good option. Wet Dry 700 is a kevlar(tm) and feldspar/ceramic thickened, structural repair epoxy past. It as about as thick as joint compound, wall mud, or cake icing. It can be applied underwater for emergency repairs too. While it is thick, it can also be used with fiberglass cloth for more strength and to fill and cover larger gaps and cracks. It is one of our most popular epoxy compounds and more information about Wet Dry 700 on our FAVORITES (click here) page.

 

If the issue is just corrosion or pitting or leaking rivets, then the fix is one or two coats of our MCU aluthane aluminum paint. (click here for more info on aluthane). MCU (moisture cured  urethanes) are special coatings that are attracted to moisture  and since Aluthane is very thin, these two factors get it into tiny cracks and spaces for a wonderful corrosion stopping coating. It also looks good, like a new aluminum boat. It does not need to be top coated.

 

Because epoxies do not like sunlight, it is recommended you paint over the CM 15 epoxy that is exposed to the sunlight (if not right away, then next season). Best is to paint over the CM 15 with a coat of aluthane. Stop with the aluthane or paint over the aluthane with an enamel or poly paint in whatever color you want. While it is a good idea to use the aluthane as a primer, under the colored paint, it is not required. You can just use the poly/enamel directly over the CM 15 epoxy.

 

You can 'seal' leaking rivets, etc. with 1 or 2 coats of aluthane and then epoxy top coat. However, it is not advised to paint the entire hull with aluthane and then apply the CM 15 over it. Epoxy first (except for spot coating) and then the Aluthane on top of epoxy. Pigmented 'regular solvent based paint" (if you want) over the CM 15 epoxy paint or over the Aluthane.

 

Need to order products or talk about your pontoon project?

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