bedding bolts

[BlackHeron]

Originally Posted by Suijin

My statement was based on direct experience over the years. Most recently (a couple of months ago) for example, I bedded my stern cleats with Bed-it, which I don't consider a cheap product (like the RV stuff). The temperature in the shed was about 90 F. I have a fairly good feel for when 5/16" stainless bolts are well torqued (and applied Tef-gel where the nuts and washers go on to prevent galling). I've not been as careful in the past with butyl application but in this case followed RC's directions to the letter, with the entire foot of the cleat getting an even layer of butyl, rings around the bolts, chamfered holes, etc. It took three tightening sessions to get the nuts tight, each round being fairly "aggressive". It was important to get it right as once the propane locker insert was reinstalled access to the nuts would be extremely difficult. I had the same experience with other fixtures I mounted with Bed-it (clutches, winch bases, etc.).

Don't get me wrong, I'm not criticizing Bed-it as a bedding compound. I think it's great. If I didn't think so I would not be using it at all. And maybe in the grand scheme of things the actual application time is the same.

Last year I re-bedded every single though-deck on our boat, after going through and over-drilling, and then filling in with thickened resin, and drilling again right-size holes and counter-sinking and tapering everything before painting the area around them. That's pulpit, stern rail, 10 stanchion bases, 6 cleats, supports for wind generator pole, 3 liferaft cradle feet, monitor wind vane supports, chainplanes, fuel, water, and pumpout deck fittings, mast glands, aftdeck glands, (LP, LP solonoid, solar power, wind power) everything.

I used butyl for all if it. 3 rolls of it. I have used butyl extensively in the past working on our club boats when we did similar deck jobs on those. I didn't have any of the issues you described with butyl tape.

I'm an electrician who builds large electrical switch-gear as primaries for huge commercial/industrial buildings, factories, and high-rises. We have these special tools called "torque-wrenches," they are exotic and rare devices that are apparently not very well known in the rest of the world. These allow us to put constant toque forces on bolts according to their size and composition. This is very important here, since two copper bus bars connected with a bolt that is not properly torqued can fail causing an electrical fire and burn an entire building down.

Even though I've probably torqued 100,000 or more fasteners with a torque wrench in my career I still believe that "feel" is BS, even for someone who has torqued thousands of bolts. Every single weird angle one has to contort oneself into in order to position a wrench over a fastener changes that "feel" considerably. If in ANY doubt use a torque wrench to monitor the torque you are using, even if it is only from time to time to constantly monitor the "feel" of what you are doing.

We also use butyl at work in water-tight enclosures and gear. It's what comes with the equipment. Rarely do these come with an adhesive sealant as they are one-time sealants and electrical gear often needs to be disassembled to maintain them. Butyl tape is easier to clean off and reapply subsequently for all the reasons it is on a boat.

In the end it is your boat. Use what you feel is best, and you are most experienced using successfully. That's what this thread is all about. The OP asked what worked for people and what they liked best and why. I stated my reasons. They work for me. If you have issues that I haven't encountered then perhaps my experienced are limited, having only used butyl successfully for a few years in the marine environment, and decades in the commercial/industrial electrical trades.

That said, I have run into many situations when removing adhesive sealants, where the task has substantially been made more difficult and extremely time-consuming due to the choice of material used by the last installer. These jobs took 3-4 times as long and I can remember times spending hours, cursing the whole time, just trying to clean up and prep one single thru-deck or through-hull. What a PITA. Had they used butyl I'd have been done. A bit of mineral spirits and a scraper and it's GONE. I really dislike it when I run into silicone-based sealants. Those take forever. Miss a little bit in the wrong place and it WILL leak. Nothing sticks to cured silicone -not even new silicone. It guarantees failure. I don't care what you use on your boat, as long as it isn't silicone on a boat I'll need to work on someday. In that case I'll be cursing you so hard you would feel your ears burning all the way on the other side of the planet.

Your mileage may vary.

[Suijin]

Originally Posted by BlackHeron

That said, I have run into many situations when removing adhesive sealants, where the task has substantially been made more difficult and extremely time-consuming due to the choice of material used by the last installer. These jobs took 3-4 times as long and I can remember times spending hours, cursing the whole time, just trying to clean up and prep one single thru-deck or through-hull. What a PITA. Had they used butyl I'd have been done. A bit of mineral spirits and a scraper and it's GONE. I really dislike it when I run into silicone-based sealants. Those take forever. Miss a little bit in the wrong place and it WILL leak. Nothing sticks to cured silicone -not even new silicone. It guarantees failure. I don't care what you use on your boat, as long as it isn't silicone on a boat I'll need to work on someday. In that case I'll be cursing you so hard you would feel your ears burning all the way on the other side of the planet.

Your mileage may vary.

No doubt. My boat was built in '86, back when 5200 was king, and every last piece of hardware, including the port lights, was bedded with it. I have removed and rebedded everything at this point, and at times needed a torch and a car jack to do it. So I'm extremely familiar with issues surrounding curing adhesive sealants. But out of probably 350 bolts and screws removed only one had leaked, and only minimally. Based on that performance I was sorely tempted to put everything back on with 5200 and let the next person deal with it in another 30 years. There are pros and cons to every material.