On Wednesday I ground the new glass close to flat and flush, using a straight edge to find and mark the high spots. 
I got to wear my new Wes Cravens designed grinding outfit, hoping to mostly avoid the infamous fiberglass itch.
Next followed three cycles of filling the low spots with Microlite putty and fairing it flush and flat with the manual sanding board (torture board). A foot-wide $3 plastic smoothing tool was a great help in applying the putty flat and smooth across the entire area.
The rain predicted for Thursday was delayed, so I was able cut out the holes for the new ports using my big hole saw and new jig saw. As anyone who's done it will tell you, cutting big holes in your boat, even above the waterline, is always traumatic. "Measure twice, cut once" was a mantra I repeated over and over. Careful use of drilling and cutting guides helped it go smoothly.
Cut-outs showed that my laminations were good: no gaps, all the mat layers fully saturated with resin A little grinding to round the inner edges and the ports slid into the new holes perfectly. Whew!! I coated the newly-exposed edges of the plywood interior liner with epoxy so it wouldn't absorb water and rot in the event of (Heaven forbid!) a leak. While I waited for the epoxy to cure, I cut and applied butyl tape to a porthole flange. In addition to the flat cut pieces of butyl around the outer flange, I added a strip around the corner where the inner and outer flanges meet at a 90 degree angle. The theory was that it would squeeze out between the inner flange and the edge of the hole, resulting in a good seal. 
The epoxy around the hole on the sunny side cured quickly enough for me to try to bolt in the port. I soon discovered that my newly-purchased bronze machine screws were too short to extend through both the uncompressed butyl and the mounting flange. Damn! After a few moments of high anxiety, I thought I might be able to use a couple of clamps to compress the butyl enough to get the screws through. By repeatedly clamping and reclamping around the perimeter and using a lot of clamping pressure, it worked like a charm. 
The individual butyl pieces welded to each other nicely, and the excess squeezed out between the flange and the hole as I had hoped. 
Of course some also sqeezed out around the inside mounting flange on the cabin side, but that was easily removed simply by cutting around the flange with sharp knife and lifting off the excess.
At this point, the epoxy around the hole on the shady side still wasn't cured, it was getting late, the rain was coming in, and I was beat-all good reasons to call it a day and head home.
It rained Friday and Saturday, so I continued with the shop projects. I rounded the corners on the mast support post cover, cut matching bungs from scrap jatoba and glued them in place on one side. 
On the other side (the piece that will be screwed on during installation) I mounted a teak grab handle. No, I didn't make it. At twelve bucks (even at Worst Marine), it wasn't worth the time. 
The next morning, after the glue had set, I trimmed the protruding bungs flat using a flushcut saw. 
I find it works better than using the usual chisel method. Even with a sharp chisel and thin cuts, I usually end up with some of the bungs breaking off below the surface. The flushcut saw doesn't scratch the surface and results in the bung trimmed so close to the surface that normal finish sanding is enough to make it perfect. Finally, finish sanding of the post cover pieces, and between-coats sanding of the varnish on the table parts. Last thing Saturday was to apply varnish all around.
Sunday was a beautiful day. I installed the second port as I had the first and applied a bead of 3M 4000 UV around the ports to finish off the installaton and create a redundent outer seal. 
With some white plastic caps to cover the protruding nuts and bolts, it will be a pretty clean installation. I cleaned up the week's mess (well, mostly), and called it a good week.
This is so advanced stuff beyond your typical maintenance and repair, george, leaves my jaw hanging that I would ever be able to do any of that.
ReplyDeleteJust some questions for the record:
- How many layers total did that come out to be?
- What exactly (step by step) did you do to saturate and fill each of those layers?
- Did you have any issues with hardening before you started cutting away? Isn't there a large cure time, especially that thickness and given the anticipated humidity?
- You did ALL of them last week?
- Not sure what prompted you to build a cover for the mast support. Don't you want to be able to view this in case there is trouble?
Anyway, that was intense to read to say the least!
Salty Monkey,
ReplyDeleteThanks for so deligently wading through all this! My responses to your questions and comments follow in two parts (more characters than allowed in one comment....)
"This is so advanced stuff beyond your typical maintenance and repair, george, leaves my jaw hanging that I would ever be able to do any of that."
Not at all. You could do any of this stuff; none of it is rocket science. Some of it takes a little experience, which you get by screwing up. Fortunately, I've found that just about every mistake can be fixed; it just takes time. Fiberglass work can really create a big mess if you don't know how to handle it, so it helps to read up on it and/or get some help from someone who's done it your first time.
"- How many layers total did that come out to be?"
20 (4 cloth, 16 mat). Not exactly properly engineered from a composites standpoint, but plenty strong enough just because of the sheer bulk thickness.
"What exactly (step by step) did you do to saturate and fill each of those layers?"
1) Pre-cut the pieces of cloth/mat for all the layers (rough and oversize because it's faster, easier and better to grind off the extra than to try to be precise)
2) Mixed up a batch of epoxy resin. I mixed enough to saturate many layers and worked fast. (It would have been better to do a few at a time, allowing them to set before adding more layers. See below....)
3) Wet the surfaces (plywood and existing fiberglass) with resin, layed on the first layer of cloth. The resin will hold the cloth in place long enough to allow you to lay on more resin to saturate it.
4) Laid on the next layer of cloth/mat, applying the resin with a throw-away brush and then using a small squeegee to press the resin into the mat/cloth, spread it evenly and stick it to the previous layer.
5) Repeat 15 times (until thickness is adequate)
"Did you have any issues with hardening before you started cutting away?"
No; I cut all the fabric/mat before I started applying resin. (If that's what you're asking....)
...Continued in following comment
(Continued from previous comment)
ReplyDelete"Isn't there a large cure time, especially that thickness and given the anticipated humidity?"
No; the resin cures faster when it's thicker because the chemical reaction of curing releases heat, which warms the resin, which makes it cure faster, which makes it get warmer, which makes it cure even faster and so on and so on in a chain reaction. In fact, because of the volume, you have to be careful with containers full of catalyzed resin "going off" and getting hot enough to be dangerous. There are different types of epoxy available with different curing speeds. Polyester resins tend to "go off" more quickly and more suddenly than epoxy. The trick is to match the "pot life" (the time the catalyzed resin remains liquid in the pot) with the amount of time you think it will take to use it up and finish what you want to accomplish. I've wasted plenty of expensive resin calculating wrong.
"You did ALL of them last week?"
I did two ports last week. I did 4 layers of cloth one day and 16 layers of mat the next day for each port. It would have been better to do the layers in groups of 4 or 5, allowing them to cure enough to stay in place, because the weight of 16 saturated but uncured layers caused the big "sandwich" to have a tendency to slide down out of position. I had to continually reposition and re-squeegee it until it cured enough to be sticky and stay in place. A PITA, but the end result was fine.
"Not sure what prompted you to build a cover for the mast support. Don't you want to be able to view this in case there is trouble?"
Naked, it's a big ugly pole right in the middle of the main cabin. It was originally covered. It's not something I'm worried about. Like almost everything on these old Salars, it's overbuilt. It's been fine for 40 years and I expect it will continue to be. If I ever felt the need to inspect it, it would mean removing 10 bungs and 10 screws-not a big deal. The cover will fit snuggly, so in the unlikely event the post ever bent significantly, it would probably either crack the wood or pull the cover apart.
"Anyway, that was intense to read to say the least!"
It was pretty intense to do! Documenting it all in the blog makes me realize how hard I worked. I'm still recoverying!
Amazing and dramatic. Love the inclusion of the work uniform! And a great education on fiberglas/resin work. Look forward to seeing those port holes mate.
ReplyDeleteThanks Carol! Many people have told me that the full fiberglass cover-up is definitely my best look!
ReplyDeleteCapt G and Admiral C. Thanks for the details which go down in the boat maintenance history books. Although I have cold molding experience with ply over frame and smaller necessary fills, the thickness you had to deal with compounded by the timeframe you worked is truly mind bogging.
ReplyDeleteWhats particular amazing is how you are able to lay down so many layers and not have gravity play tricks on you because of the vertical angle. Then following up in a day with cutting it up for millimeter fitting ARRG!
As for the post box, my only armchair comment is you should have built a little door or some mini-drawers in there so you can utilize the inside for some storage (spices? parts?) and for inspection. It will be interesting to see what happens once sailing and how it will flex around.
Looking forward to next time. =)
SM:
ReplyDeleteAs I said, I did have some trouble with all those layers slipping; it would not have been an issue if I did fewer layers at a time.
Not to beat a dead post to death, but there is no room between between the post cover and the iron post; it's snug. If you think it's going to flex a lot, you haven't been on a Salar. They are tanks. You can jump on my deck and it's like concrete! But the boat will actually sail!!
aww rats. was dreaming about little bars of chocolate hidden in small drawers on the post =)
ReplyDeleteOk, preparing myself for another round this weekend coming. weather looks AOK so far.
All the best
SM