Removing bondo and doing it right

[Scottwid]

I bought a couple older seadoos last fall that need some love. One of them is a 96 gti that has been sanded and patched in areas (skim coated with bondo). I think they were attempts to repair spider cracks. The ski has not been in the water since these attempted repairs.

I have researched how to fix this the right way and haven’t found an explanation for this exact situation. As I understand it the bondo has to go. It has been sanded to the fiberglass in several areas. What would be the proper way to fix this? I am new to jet skis but am a very diy guy. Your guidance is appreciated!

 

[GGuillot]

I bought a couple older seadoos last fall that need some love. One of them is a 96 gti that has been sanded and patched in areas (skim coated with bondo). I think they were attempts to repair spider cracks. The ski has not been in the water since these attempted repairs.

I have researched how to fix this the right way and haven’t found an explanation for this exact situation. As I understand it the bondo has to go. It has been sanded to the fiberglass in several areas. What would be the proper way to fix this? I am new to jet skis but am a very diy guy. Your guidance is appreciated!

Sand it down, die grind the cracks out to create like a little channel, then fill with Marine Tex. After it's dry, sand it smooth, and for a finished look gelcoat over it.

Unless it's structural damage, Marine Tex and some gelcoat will work fine, you can buy both in small amounts if you're just trying to fix up a bad spot.

 

[Scottwid]

Sand it down, die grind the cracks out to create like a little channel, then fill with Marine Tex. After it's dry, sand it smooth, and for a finished look gelcoat over it.

Unless it's structural damage, Marine Tex and some gelcoat will work fine, you can but both in small amounts if you're just trying to fix up a bad spot.

Thanks! That’s what i was looking for. There are some areas around 1x3 inches that have been sanded all the way to the fiberglass. How do I build those places back up?

 

[Scottwid]

I took a photo of one of the sanded areas for reference. Is there anything between the fiberglass and gel coat in the process at the factory? Can i scuff sand these areas and then build gel coat over it, or is there supposed to be something in between? This area is approximately 5 inches wide.

 

[Kwik_uk]

Just looks like keel rub? Can’t really make out the angle. For something that fine you could always just do a light gel. There’s plenty of places online where you can use your HIN to look up your colour.

If you want it flat, check it with a metal rule too see how deep the curve is.

Die grind out a small channel as mentioned above, clean out with acetone (help start get the gel ready for adhesion too), then build back up with a couple of ripped small strips about 3/4 the width of your channel with nice fine chopped mat. It’s neater to rip rather than cut. OR make some “peanut butter” up using some poly gel and a scoop of chopped stand fibres. This won’t be as strong, but from that picture I can’t see even this is needed.

Let it all harden, sand it down again to about 180 and check again with metal rule, it should be ever so slightly lower than your current top coat. Then you can either gelcoat it, or personally I’d flow coat it (it’s just gelcoat with some wax in so you don’t need to cover it to harden. If no flow coat, use gel coat and cover with either self adhesive wax paper (I like the 1mm thick 50cm2 panels) or a similar non stick film.

Wet sand back with a flat block and go down the grits till you pass 1000, then I’d switch to a little rubbing compound (3M, Farecla, Megs etc) and go down a couple of levels with that too. Then wax and enjoy.

If that sounds complicated or you want any extra info just let me know. Currently responding via phone app from Covid19 lockdown hence my lack of pictures/grammar[emoji23]

There’s literally thousands of videos on this which I really think will make it much easier. Just have a look on YouTube for gelcoat repair and look for someone doing a repair for gel coat rubbing through on keel or just type “keel rash repair” [emoji1303]

 

[beergut]

for severe cracks or damage, i sanded down the cracks and rebuilt it up using fiberglass cloth and resin- then sanded, then gel coat. bondo isn't structural and will just crack out over time as the hull vibrates. the resin & cloth is structural and provides support. quick tip i learned while using the resin & cloth; after applying the resin soaked cloth to the hull, cover with plastic wrap to smoothen the area out and minimize sanding. it worked really well.

 

[Kwik_uk]

for severe cracks or damage, i sanded down the cracks and rebuilt it up using fiberglass cloth and resin- then sanded, then gel coat. bondo isn't structural and will just crack out over time as the hull vibrates. the resin & cloth is structural and provides support. quick tip i learned while using the resin & cloth; after applying the resin soaked cloth to the hull, cover with plastic wrap to smoothen the area out and minimize sanding. it worked really well.

Massive agreement here from me. I’d never use bondo (we call it bodge or just body filler in the UK), unless it was an emergency/weekend fix. It is useful for certain things, but for a quality finish that isn’t going to be covered by anti foul, then doing it properly is the only way to go. Good practice too, trust me. This won’t be the first time you’ll need to do this in the PWC/boating world.

 

[Scottwid]

Yeah the bondo ‘fix’ was from the previous owner’s employee who wanted to be helpful. Apparently he was fired over it.

So if it’s just rubbed through in spots (sanded actually) i can gel coat over it? There are no gouges or structural cracks. If that’s the case I’ll be very happy. As a second question, can you spray gel coat with an hvlp gun? If so, what tip size?

thanks for the great info, guys!

 

[Major Woody]

Yeah the bondo ‘fix’ was from the previous owner’s employee who wanted to be helpful. Apparently he was fired over it.

So if it’s just rubbed through in spots (sanded actually) i can gel coat over it? There are no gouges or structural cracks. If that’s the case I’ll be very happy. As a second question, can you spray gel coat with an hvlp gun? If so, what tip size?

thanks for the great info, guys!

Have a close look at the cracking. Put a light inside the hull behind the cracking. Is it structural? What exactly is cracked? You will need to address the cracking and remove the cracked gelcoat and make a proper repair using fiberglass. You may be able to add layers of resin and mat to the inside of the cracked area to thicken and strengthen it. The gelcoat work over the top is similar to paint, just thicker. You will be super bummed if you repair the gelcoat and then the cracks reappear.

Bondo also absorbs water and has no place on a watercraft.

 

[Scottwid]

Thanks for the tips. I think there are some places that will need some structural repairs. Just to be clear, the bondo is coming off regardless of the route i take.

 

[ski-d00]

West Systems fiberglass repair for structural repairs. Have used this several times fixing holes bigger than a football and the epoxy is better than the old polyester resin method the way the boat was made. Epoxy just grabs better and doesn't seem to crack out the way resin patches do. Ends up being stronger than the original.

 

[mikidymac]

I have found the best place to get epoxy resin and fiberglass cloth is US Composites. I didn’t care for the quality of the last glass I got from Jamestown.