Shhh... you're not supposed to tell them this...
HS—
Post a photo if you can... I am having a hard time imagining why someone would do something like this... and not repair it properly...
Glassing in backing plates for through hulls
- Thread starter Hermit Scott
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HS—
Post a photo if you can... I am having a hard time imagining why someone would do something like this... and not repair it properly...
description of hole
"properly" is a very relative term in the eye of the repairer.
This hole was perfectly round, 3/8" by my guess. The angle is about 10 degrees angled down from the bilge. It is on the portside a few inches from the front keel bolt. Inside the bilge the hole starts at the edge where the bilge floor meets the bilge wall.
When it was puttied up, it was only done from the outside. So the hole was always visible from the inside, that is where I first noticed it.
The hole is drilled at the lowest point and drilled so any water will drain out.
I can't see any other reason for drilling a hole than this. After all, it wouldn't work very well once the boat was back in the water.
"properly" is a very relative term in the eye of the repairer.
This hole was perfectly round, 3/8" by my guess. The angle is about 10 degrees angled down from the bilge. It is on the portside a few inches from the front keel bolt. Inside the bilge the hole starts at the edge where the bilge floor meets the bilge wall.
When it was puttied up, it was only done from the outside. So the hole was always visible from the inside, that is where I first noticed it.
The hole is drilled at the lowest point and drilled so any water will drain out.
I can't see any other reason for drilling a hole than this. After all, it wouldn't work very well once the boat was back in the water.
Sounds like the boat was on the hard neglected for a while. It isn't unusual for someone to put a hole in to stop rainwater from causing potentially greater damage. Not much of a concern where you are, but my boat has a very deep bilge and a proper drain fitting would be handy for washing out the bilge and ensuring that standing water doesn't freeze in winter. Does anyone have one for that purpose?
It is also not unusual for folks up here to pop a couple of holes in their rudder for the winter if it is waterlogged as if the water isn't allowed to drain out it will freeze and split the rudder down the edges. Been there and done that on my last boat. My current boat's rudder is sound, so I passed on the drilling this year.
It is also not unusual for folks up here to pop a couple of holes in their rudder for the winter if it is waterlogged as if the water isn't allowed to drain out it will freeze and split the rudder down the edges. Been there and done that on my last boat. My current boat's rudder is sound, so I passed on the drilling this year.
I used sikiflex and installed all the through hulls and flange plates. I just let it squish out from under the plate in the boat and left it like that. On the out side, I tried to wipe up as much as I could, but it's still all over the through hull and in the countersunk holes with the bolt heads in them. I didn't want to clean it up with acetone for fear it might damage the seal if I used too much.
I had to sand the outside so the through hulls sat flush with the hull. I have some fiberglass work to do there to cover up the holes with the bolts in them and fill in around the mushroom heads on some of them.
I don't want to use 3M filler. The epoxy will be relatively thin. What do I mix with the epoxy to make it paste like? Are some of the fillers for epoxy good below the waterline and some not good below the waterline?
Maine sail mentioned in another post about a filler that, when sanded, absorbed water and casued the paint not to stick.
I had to sand the outside so the through hulls sat flush with the hull. I have some fiberglass work to do there to cover up the holes with the bolts in them and fill in around the mushroom heads on some of them.
I don't want to use 3M filler. The epoxy will be relatively thin. What do I mix with the epoxy to make it paste like? Are some of the fillers for epoxy good below the waterline and some not good below the waterline?
Maine sail mentioned in another post about a filler that, when sanded, absorbed water and casued the paint not to stick.
Microballoons or microfibers
MIcroballoons are tiny spherical glass particals, looks like powder in the can, that when mixed with epoxy will make it thick. You want the consistency of peanut butter and since you are working upside down or on a vertical surface put saran wrap over it and duct tape to hold it in place so it doesn't run out. The saran wrap will leave a perfectly smooth surface if you get all the wrinkles and bubbles out. Since the microballoons are not continuous in the final product there is little chance of water infusion. They also add strength to the material by adding discontinuities that help prevent cracks from propogating. Microfibers also work good for thickening up the epoxy but I think they are better for bonding things together such as two boards or for instance bonding your backing plates to the hull. The fibers may allow more water intrusion, more like glass clothy but I think the risk is minimal. The microballoons will likely give a better smooth surface. The microfibers when you sand it smooth will leave some fiber ends exposed that water can then wick along.
You can make your own fibers by just cutting some glass cloth with scissors into very fine lengths.
MIcroballoons are tiny spherical glass particals, looks like powder in the can, that when mixed with epoxy will make it thick. You want the consistency of peanut butter and since you are working upside down or on a vertical surface put saran wrap over it and duct tape to hold it in place so it doesn't run out. The saran wrap will leave a perfectly smooth surface if you get all the wrinkles and bubbles out. Since the microballoons are not continuous in the final product there is little chance of water infusion. They also add strength to the material by adding discontinuities that help prevent cracks from propogating. Microfibers also work good for thickening up the epoxy but I think they are better for bonding things together such as two boards or for instance bonding your backing plates to the hull. The fibers may allow more water intrusion, more like glass clothy but I think the risk is minimal. The microballoons will likely give a better smooth surface. The microfibers when you sand it smooth will leave some fiber ends exposed that water can then wick along.
You can make your own fibers by just cutting some glass cloth with scissors into very fine lengths.
yes
The issue is how perfect at a microscopic level is the bonding? How big is a water molecule. Let's see two hydrogen atoms and an oxygen atom. The hydrogens are the smallest atoms. The oxygen is number 8 on the periodic table. So combined a pretty small molecule. By comparison the carbon based epoxy is a gigantic molecule that links with other gigantic molecules. In a lattice there will be all kinds of atomic defects, vacancies, dislocations, etc. Water will find it's way into all these voids and defects. It will also wick along the fibers wherever there is a defective bond. Frankly you are worrying too much. I would use either the microballoons or the microfibers and sleep well at night.
The issue is how perfect at a microscopic level is the bonding? How big is a water molecule. Let's see two hydrogen atoms and an oxygen atom. The hydrogens are the smallest atoms. The oxygen is number 8 on the periodic table. So combined a pretty small molecule. By comparison the carbon based epoxy is a gigantic molecule that links with other gigantic molecules. In a lattice there will be all kinds of atomic defects, vacancies, dislocations, etc. Water will find it's way into all these voids and defects. It will also wick along the fibers wherever there is a defective bond. Frankly you are worrying too much. I would use either the microballoons or the microfibers and sleep well at night.
Once I get to my slip I can do and redo anything that needs to be done except this. If I have to redo any of this, the boat has to be hauled.
I repaired some blisters before I knew about epoxy versus polyester. The only thing stopping me from ripping those out and redoing them is that I sealed them with interlux 2000e.
I just want to make sure I don't do some bonehead move and it's something I am worrying about down the road.
I repaired some blisters before I knew about epoxy versus polyester. The only thing stopping me from ripping those out and redoing them is that I sealed them with interlux 2000e.
I just want to make sure I don't do some bonehead move and it's something I am worrying about down the road.
Barrier Coating
If you are barrier coating the epoxy over the screw heads it should be waterproof and you don't need to worry about wicking or moisture. With microfibers they are all randomly oriented so inevitably some of the fibers will be oriented perpendicular (or at a steep angle) to the hull giving the water a wicking path into the epoxy. You were concerned about paint adhesion. Bottom paint is not water proof anyway so presence of moisture is not a factor in adhesion to the surface except when it is coated originally. You just need a good surface for the paint to adhere, the interlux is recommended as a priming coat to help with paint adhesion, you may want to lightly sand the epoxy, slap on a couple coats of the inturlux 2000 if you have any left, then bottom paint over that. When I ground all the paint off my lead keel and sealed it with west epoxy I threw a couple coats of interlux over the epoxy to help with paint adhesion. Why did I seal the lead keel? oxidized lead will not allow paint to adhere well so I sanded it all off (wear a respirator approved for lead dust) put a couple coats of WEST epoxy, used a wire brush to work it into the lead, cure it, then the interlux bottom coat followed by bottom paint. Much less work on haul outs to add a couple coats of paint versus scraping and sanding related to poor adhesion.
If you are barrier coating the epoxy over the screw heads it should be waterproof and you don't need to worry about wicking or moisture. With microfibers they are all randomly oriented so inevitably some of the fibers will be oriented perpendicular (or at a steep angle) to the hull giving the water a wicking path into the epoxy. You were concerned about paint adhesion. Bottom paint is not water proof anyway so presence of moisture is not a factor in adhesion to the surface except when it is coated originally. You just need a good surface for the paint to adhere, the interlux is recommended as a priming coat to help with paint adhesion, you may want to lightly sand the epoxy, slap on a couple coats of the inturlux 2000 if you have any left, then bottom paint over that. When I ground all the paint off my lead keel and sealed it with west epoxy I threw a couple coats of interlux over the epoxy to help with paint adhesion. Why did I seal the lead keel? oxidized lead will not allow paint to adhere well so I sanded it all off (wear a respirator approved for lead dust) put a couple coats of WEST epoxy, used a wire brush to work it into the lead, cure it, then the interlux bottom coat followed by bottom paint. Much less work on haul outs to add a couple coats of paint versus scraping and sanding related to poor adhesion.
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