Bolt Hole Through Hull Repair

[Frenchy93]

I'm actually kind of embarrassed to post this but here we go.

I bought a tunnel hull at the end of last season to find out the previous owner had bolted aftermarket seats THROUGH the hull. I want to seal up the hole and do it properly.

What are some suggestions for doing this? Just fill the holes with resin? If this is the best way how do you suggest sealing the hole at the bottom so resin doesn't drip through.

Here's some pics of the holes. As you can see the previous owners brilliant idea was to cover the holes in foil tape LOL

http://imgur.com/aUU40RB

http://i.imgur.com/aUU40RB.jpg

 

[Woodonglass]

Do you have access to the holes from the topside? If so, then remove the bolts. Use a dremel or drill with an abrasive bit to clean the holes and scuff the surrounding area about 3" out. Tape over the holes on the outside and then from the inside fill em with thickened polyester resin. then using some 1708 fabric cut some circular patches, first one 11/2" in diameter and the second 3" diameter. Lay the small one first followed by the second one. Go to the outside and remove the tape. On the outside, apply two CSM circular patches and then sand and fair the outside surface. Then apply 3-4 coats of matching red gelcoat. Wet Sand thru 1000 grit and she'll be good as new. Mixing and Matching RED gelcoat is a BIG task. But...since it's on the bottom it's not as critical to get an exact match.

Feel free to ask more questions if you need clarification.

 

[Frenchy93]

Do you have access to the holes from the topside? If so, then remove the bolts. Use a dremel or drill with an abrasive bit to clean the holes and scuff the surrounding area about 3" out. Tape over the holes on the outside and then from the inside fill em with thickened polyester resin. then using some 1708 fabric cut some circular patches, first one 11/2" in diameter and the second 3" diameter. Lay the small one first followed by the second one. Go to the outside and remove the tape. On the outside, apply two CSM circular patches and then sand and fair the outside surface. Then apply 3-4 coats of matching red gelcoat. Wet Sand thru 1000 grit and she'll be good as new. Mixing and Matching RED gelcoat is a BIG task. But...since it's on the bottom it's not as critical to get an exact match.

Feel free to ask more questions if you need clarification.

I can access from the inside, all I gottta do is remove the seats and they are right there.

What is the point in the patches? The top will be covered by a seat and the bottom will be in the water so I doubt I will even gel coat it.

Can I get the thickened resin as any old hardware store?

 

[CrazyFinn]

Toggle boats through the hull? Seriously? Wow...

I'm sure WOG can point you in the direction of some more instructional posts, but you make thickened resin yourself. Basically, polyester resin thickened with some other product such as Cabosil (fumed silica). That provides the basic thickness. The fabric provides the strength. Resin without the fabric will eventually crack and pop out of the hole.

 

[Frenchy93]

Toggle boats through the hull? Seriously? Wow...

I'm sure WOG can point you in the direction of some more instructional posts, but you make thickened resin yourself. Basically, polyester resin thickened with some other product such as Cabosil (fumed silica). That provides the basic thickness. The fabric provides the strength. Resin without the fabric will eventually crack and pop out of the hole.

The purchase of this boat resulted in a small claims case lets just say that and I won. The holes were hidden by the trailer bunks.

Crazy, what happens if I don't use a thickened resin and just use straight resin?

 

[jbcurt00]

Unthickened its likely to sag or run out of the hole, besides, polyester resin NEEDS something added to it for strength, otherwise it'll crack and fail. Glass or thickening w cabosil, fumed silica or other NON-wood sawdust choices.

 

[Woodonglass]

Polyester Resin when cured, becomes very brittle and will eventually crack and allow water intrusion. The method described is the proper method for the repair. You Don't have to gelcoat it and could leave the resin exposed but you MUST use the CSM. I Guess you could just Plug the holes with Some PC-11 (Home Depot) but there's an outside chance the plugs could work loose. I'd highly recommend doing the repair as described in order to ensure long term success. How Big are the holes? 1/4" or larger: If only 1/4" then I guess the PC-11 filler would prolly get the job done and last long term. PC-11 is an expoxy product and does not require glass to keep it from cracking. It adheres quite well and will not crack. I'd use a small rat tail file to ensure the surface was adequately prepped before applying the sealant. I'd also use some Oil Based Acrylic enamel to paint over the patch just to add some UV protection for the epoxy. Not absolutely necessary for this small of an area and since it's below the water line. Not much sun under water!!!!

http://www.homedepot.com/p/PC-Produc...Q&gclsrc=aw.ds

 

[CrazyFinn]

I Guess you could just Plug the holes with Some PC-11 (Home Depot) but there's an outside chance the plugs could work loose. I'd highly recommend doing the repair as described in order to ensure long term success. How Big are the holes? 1/4" or larger: If only 1/4" then I guess the PC-11 filler would prolly get the job done and last long term. PC-11 is an expoxy product and does not require glass to keep it from cracking. It adheres quite well and will not crack. I'd use a small rat tail file to ensure the surface was adequately prepped before applying the sealant.

Hard to tell the scale in the photos, but those holes look too big (to me) to be plugging without some glass for reinforcement.

 

[redneck joe]

Do exactly as WOG tell you to.

 

[Frenchy93]

Hard to tell the scale in the photos, but those holes look too big (to me) to be plugging without some glass for reinforcement.

Id honestly say they are 1/2 to 3/4. I can't believe someone would do this to a boat to be honest.

 

[CrazyFinn]

In that case, just follow the instructions WOG gave you - using glass for reinforcement, both sides, so the holes stay plugged and you can forget about it and enjoy the boat. Best to just do it properly the first time.

People do really dumb things with boats. We've all seen it...

 

[Woodonglass]

Yup if they're that big then you need to fill and glass the holes as described in my first post. It's easy to do and I'd check local body shops and see if they would sell you the materials you'll need. It won't take much.

1 qt of Resin and appropriate hardener
2 qts of Cabosil or Silica
1 sq ft of 1.5oz Chopped Strand Mat
1 sq ft of 8oz cloth or heavier

Let us know when you're ready to do the repair. We'll be happy to walk you through it.

 

[Frenchy93]

Yup if they're that big then you need to fill and glass the holes as described in my first post. It's easy to do and I'd check local body shops and see if they would sell you the materials you'll need. It won't take much.

1 qt of Resin and appropriate hardener
2 qts of Cabosil or Silica
1 sq ft of 1.5oz Chopped Strand Mat
1 sq ft of 8oz cloth or heavier

Let us know when you're ready to do the repair. We'll be happy to walk you through it.

So, of course the place I go to has everything but thickener.

I did see this stuff on the shelf though what is your opinion on this? Resin with fiberglass strands to hold it together.

http://bondo.com/featured/bondo-glass-fiberglass-reinforced-filler-272.html

 

[Scott Danforth]

WOG has you covered, however Whiskey Tango Foxtrot on the toggle bolts thru the hull.

the Bondo brand body filler is made with talc. I wouldnt use it in this application

 

[Frenchy93]

the Bondo brand body filler is made with talc. I wouldnt use it in this application

Can you explain what this means and why hahaha

 

[kcassells]

Iboats sells all of the components. The other things you are talking about are not what to use. They are convienent but that's all. Listen to the years of knowlede here for the Best way to do it 1x. :joyous:

 

[Woodonglass]

Polyester Resin is naturally Hygroscopic. Using Talc as a thickening agent for Polyester Resin makes is more susceptible to water absorption. Having said that...In this case, and only in cases where the fill area is so small and since the filler material will be covered by 2 layers of glass and resin, IMHO it would be OK to use it to fill the holes and then apply the resin and glass over it on both sides. It would take Many, Many Years of constant immersion for the filler/glass to absorb enough water to make it problematic. Bond has wax added to it and this helps with the water repellant properties. Still NOT my first choice in most cases but, as stated, in this case it will be fine. Just an Old Dumb Okie's opinion. Others may/will differ!!!

 

[Scott Danforth]

Talc absobs water. Automotive body filler as you linked above uses talc vs cabosil as its thickener.

 

[boatman37]

Do as Woodonglass says and it will be as good as new.