For those that haven't been following along, the perimeters of #78's chainplate-bearing bulkheads were surveyed to be saturated, and during removal found to be amazingly rotted. The task now at hand is to install new 3/4" fir marine ply bulkheads........
This weekend's forecast is for temperatures just barely in the 50's, so it looks like I may finally have the epoxy-curing weather I need to install these new bulkheads. This "winter, revisited" weather has been immensely frustrating with those cut and CPES'd bulkheads just staring me in the face every time I've walked into the shop for the past few weeks.
I got so antsy in fact that I built a small lamination mockup to alert me to any workability problems ahead of time. See, I've never worked with glass tape of this weight before, and I was a bit worried.
I dunno what my problem was, but I ordered 4", 6", and 8" nonwoven biaxial tape from system three WITHOUT noticing that the 4" and the 8" are a composite of the nonwoven biaxial AND 12oz of mat combined for a total cloth weight of 24oz. In its raw form, this composite tape is both heavy and STIFF. I had serious concerns about laying it to a compound curve.
The mockup proved these concerns to be unfounded. Once wet-out with epoxy, it's as pliable as any old 4oz woven tape. The unanticipated challenge is the wetting out itself. It takes some time to wet epoxy through this much fiber.
This (along with the taped-plywood tender currently under construction) is also my first time ever using Peel-Ply, and I'm kicking myself hard for not using it on previous projects. This stuff is a godsend. Handling lengths of wet tape is much easier because you have something to grab that's not going to unravel or unweave. Laying and de-bubbling is much easier because you can rub as hard as you want without fear of disturbing the fibers or squeezing out too much resin. And the fact that it takes the amine blush off with it after the cure is just the coolest thing ever. As sanding is not my favorite activity, I'm a huge fan of peel-ply.
I'm taking a long weekend (rain actually is forecast for tomorrow, so only 2 real working days) for this and cutless bearing reinstallation. Hopefully on Tuesday I'll have something good to report.
New bulkhead installation (ramble)
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Curmudgeon
- Deck Grunge Scrubber
- Posts: 48
- Joined: Fri Apr 11, 2003 1:22 pm
- Location: Land-locked Calgary, Alberta, Canada
Bulkheads
Greetings - I'm at the same point in a restoration project (not a Triton, sorry) but plan to use the biaxial fabric without the mat (DB1700). Are you going to use a closed-cell filler between the bulkhead and the hull, or are you running the bulkhead right to the hull? Some say a filler should be used to prevent hard-spots on the hull, but the West System advisor I contacted said that they run bulkheads out to the hull, fillet both sides and then tape. Thanks.
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Figment
- Damned Because It's All Connected
- Posts: 2846
- Joined: Tue Apr 08, 2003 9:32 am
- Boat Name: Triton
- Boat Type: Grand Banks 42
- Location: L.I. Sound
Cushion/fillet
I suppose you could say I'm planning a hybrid of the two techniques.
I'm going to use ordinary rigid insulation foam board as a cushion between hull and bulkhead. Last night I ran a bunch of it through my bandsaw (overkill can be fun!) so I have more than enough trapezoid-shaped stock in a few different thicknesses. Of course, the convenience of this is that the angle makes an instant fillet to the hull.
The wrinkle is that I don't have enough faith in my templating job to KNOW that I'll have an even 3/8" gap all the way around. I'm sure that some spots will be near 1/2" and others might be near zero. Because of this, I'm certain that in those tight spots I'll need to mix up some thickened epoxy and make fillets "the old-fashioned way" in order to make a proper turn with the tape.
I'm going to use ordinary rigid insulation foam board as a cushion between hull and bulkhead. Last night I ran a bunch of it through my bandsaw (overkill can be fun!) so I have more than enough trapezoid-shaped stock in a few different thicknesses. Of course, the convenience of this is that the angle makes an instant fillet to the hull.
The wrinkle is that I don't have enough faith in my templating job to KNOW that I'll have an even 3/8" gap all the way around. I'm sure that some spots will be near 1/2" and others might be near zero. Because of this, I'm certain that in those tight spots I'll need to mix up some thickened epoxy and make fillets "the old-fashioned way" in order to make a proper turn with the tape.
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dasein668
- Boateg
- Posts: 1637
- Joined: Thu Apr 03, 2003 9:09 am
- Boat Name: Dasein
- Boat Type: Pearson Triton 668
- Location: Portland, Maine
- Contact:
Peel-ply? That's a new one on me... Any more info, Figment? And/or a link? I'm curious! Thanks!
Nathan
dasein668.com
dasein668.com
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
Figment,
I, and the others I'm sure, am looking forward to hearing about how your job goes this weekend. Thanks for the report to date, and please let us know how you make out! This is exactly the kind of stuff I hoped to see here on this board.
Sounds like a good plan and well thought out beforehand. It should go as smoothly as possible!
Tim
I, and the others I'm sure, am looking forward to hearing about how your job goes this weekend. Thanks for the report to date, and please let us know how you make out! This is exactly the kind of stuff I hoped to see here on this board.
Sounds like a good plan and well thought out beforehand. It should go as smoothly as possible!
Tim
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Figment
- Damned Because It's All Connected
- Posts: 2846
- Joined: Tue Apr 08, 2003 9:32 am
- Boat Name: Triton
- Boat Type: Grand Banks 42
- Location: L.I. Sound
Bulkheads are in
Where to begin? Perhaps with a brief synopsis.
Saturday was rainy, so I spent most of it on the tender, and as far as this larger project was concerned, I merely dry-fit the bulkheads in place, expecting to find high spots that needed grinding. when I found none, I left.
Sunday got off to a later start than expected (foolish expectations!) and working alone I was only able to make 60% of the tabbing on the starboard bulkhead.
Monday again got off to a late start, but with the help of a buddy who also had the day off, everything was completed with the exception of the knee for the port aft lower shroud, which I'd left sitting pretty back home on the workbench.
Cutless bearing? what's that?
Lessons the next guy won't have to learn the hard way:
1) The notion of using tapered foam to cushion the bulkheads to the hull and make instant fillets was folly. I'm sure it's a great timesaver when cutting bulkheads to a well-fit template in new construction, but for me it just turned into a huge pain. My tolerances were actually better than I expected, something in the +/- 1/8" range, but this was still too imprecise. The foam either wouldn't fit, or would fit too losely to hold itself in place. Perhaps if a more compressible foam had been used it would have been easier.
1a) I wound up making 80% of my fillets with silica-thickened epoxy. About halfway through sunday I remembered seeing a little tip on (I think) the CLC site about using a clipped ziploc bag to make fillets cake-decorator style. This little mental breakthrough was a huge timesaver, and allowed me to use the epoxy more efficiently by creating less excess.
1b) +/- 1/8" is not too shabby when fitting to the irregularities of a 43year old hull. I attribute this close tolerance to my process of making cardboard scribe templates of the existing bulkheads prior to demolition, and using these to make "scratch" templates of luan plywood, which were fitted and re-scribed to the hull after the existing bulkheads had been removed. Template twice, cut once. Or something like that.
2) As the mockup taught me, the heavy tape laid very easily once wet-out, but wetting out was a challenge unto itself. My limited progress on sunday was due to the fact that I was spending at least 2/3 of my time mixing resin and wetting cloth. Having a helper today made all the difference in the world. Ideally, it's a three-person team effort. One constantly mixing cups of epoxy, one measuring, cutting and wetting tapes, and the third laying the laminate and rolling bubbles.
3) I grossly underestimated the time and amount of epoxy required to wet out cloth of this weight. I had to run for more goo TWICE. Luckily, a Woodcraft store 20minutes away carries a small supply of System Three products (otherwise only available direct from S3 in Seattle). Total consumption on this project will exceed two GALLONS of resin and a gallon of hardener. I'm sure that if I'd placed my S3 order over the phone, the person on the other end would've red-flagged this oversight. One drawback to the convenience of e-shopping.
3a) I also grossly underestimated the number of disposable gloves I'd go through. 120+ I consider this $15 well spent, given lesson #4...
4) Don't kid yourself about this being an only moderately messy job. Yes, you WILL stick to everything, and yes, everything WILL stick to you. Don't be bashful about changing gloves every time you begin a new task. Wear a longsleeved shirt and pants that you will throw away. In retrospect, a shower cap would've been a good idea too.
5) Do what you can ahead of time to get all of your substrate to one even color tone. I wasted a lot of time in the early pieces obsessing over what I thought to be air pockets, but which later I realized were just whitish patches of the hull fiberglass.
6) Yes, handling and laying a 24" length of wet laminate through the v-berth storage hatches is as difficult as you think it is. You will invent new words, and you will twist in ways you'll only feel later that night. In retrospect, I'm sure that three 8" sections would be just as strong and manageable with one hand, but my brain was in a "continuous strips" groove.
But with a few hours of perspective on it now, it's a worthwhile project. I consider this new installation to be near bulletproof. With a combined 60 ounces of modern fiber cloth set in epoxy binding these new epoxy-sealed bulkheads in place, I feel perfectly comfortable stating that it's Stronger Than New. If we encounter forces strong enough to part that bond...... well, screw it, the stick DESERVES to come down!
Also, if I hadn't been educated enough on the topic of Sealing All Deck Penetrations, this little ditty has driven the lesson home with gusto. ALL of the rot found in the bulkheads was due to water intrusion from the chainplate penetrations. It had initially been speculated that the rot was due to the partial-sinking that the boat experienced under previous ownership, but I discount this entirely. The lower portions of the bulkheads, while saturated, had not yet begun to rot.
I was pretty anxious going into this. It feels wonderful to have it behind me. Now to finish putting the rest of the boat back together.....
(Edited to augment and clarify my late-night hackings. Pics, of course, will follow once I get them sorted out and uploaded to the website.)
Saturday was rainy, so I spent most of it on the tender, and as far as this larger project was concerned, I merely dry-fit the bulkheads in place, expecting to find high spots that needed grinding. when I found none, I left.
Sunday got off to a later start than expected (foolish expectations!) and working alone I was only able to make 60% of the tabbing on the starboard bulkhead.
Monday again got off to a late start, but with the help of a buddy who also had the day off, everything was completed with the exception of the knee for the port aft lower shroud, which I'd left sitting pretty back home on the workbench.
Cutless bearing? what's that?
Lessons the next guy won't have to learn the hard way:
1) The notion of using tapered foam to cushion the bulkheads to the hull and make instant fillets was folly. I'm sure it's a great timesaver when cutting bulkheads to a well-fit template in new construction, but for me it just turned into a huge pain. My tolerances were actually better than I expected, something in the +/- 1/8" range, but this was still too imprecise. The foam either wouldn't fit, or would fit too losely to hold itself in place. Perhaps if a more compressible foam had been used it would have been easier.
1a) I wound up making 80% of my fillets with silica-thickened epoxy. About halfway through sunday I remembered seeing a little tip on (I think) the CLC site about using a clipped ziploc bag to make fillets cake-decorator style. This little mental breakthrough was a huge timesaver, and allowed me to use the epoxy more efficiently by creating less excess.
1b) +/- 1/8" is not too shabby when fitting to the irregularities of a 43year old hull. I attribute this close tolerance to my process of making cardboard scribe templates of the existing bulkheads prior to demolition, and using these to make "scratch" templates of luan plywood, which were fitted and re-scribed to the hull after the existing bulkheads had been removed. Template twice, cut once. Or something like that.
2) As the mockup taught me, the heavy tape laid very easily once wet-out, but wetting out was a challenge unto itself. My limited progress on sunday was due to the fact that I was spending at least 2/3 of my time mixing resin and wetting cloth. Having a helper today made all the difference in the world. Ideally, it's a three-person team effort. One constantly mixing cups of epoxy, one measuring, cutting and wetting tapes, and the third laying the laminate and rolling bubbles.
3) I grossly underestimated the time and amount of epoxy required to wet out cloth of this weight. I had to run for more goo TWICE. Luckily, a Woodcraft store 20minutes away carries a small supply of System Three products (otherwise only available direct from S3 in Seattle). Total consumption on this project will exceed two GALLONS of resin and a gallon of hardener. I'm sure that if I'd placed my S3 order over the phone, the person on the other end would've red-flagged this oversight. One drawback to the convenience of e-shopping.
3a) I also grossly underestimated the number of disposable gloves I'd go through. 120+ I consider this $15 well spent, given lesson #4...
4) Don't kid yourself about this being an only moderately messy job. Yes, you WILL stick to everything, and yes, everything WILL stick to you. Don't be bashful about changing gloves every time you begin a new task. Wear a longsleeved shirt and pants that you will throw away. In retrospect, a shower cap would've been a good idea too.
5) Do what you can ahead of time to get all of your substrate to one even color tone. I wasted a lot of time in the early pieces obsessing over what I thought to be air pockets, but which later I realized were just whitish patches of the hull fiberglass.
6) Yes, handling and laying a 24" length of wet laminate through the v-berth storage hatches is as difficult as you think it is. You will invent new words, and you will twist in ways you'll only feel later that night. In retrospect, I'm sure that three 8" sections would be just as strong and manageable with one hand, but my brain was in a "continuous strips" groove.
But with a few hours of perspective on it now, it's a worthwhile project. I consider this new installation to be near bulletproof. With a combined 60 ounces of modern fiber cloth set in epoxy binding these new epoxy-sealed bulkheads in place, I feel perfectly comfortable stating that it's Stronger Than New. If we encounter forces strong enough to part that bond...... well, screw it, the stick DESERVES to come down!
Also, if I hadn't been educated enough on the topic of Sealing All Deck Penetrations, this little ditty has driven the lesson home with gusto. ALL of the rot found in the bulkheads was due to water intrusion from the chainplate penetrations. It had initially been speculated that the rot was due to the partial-sinking that the boat experienced under previous ownership, but I discount this entirely. The lower portions of the bulkheads, while saturated, had not yet begun to rot.
I was pretty anxious going into this. It feels wonderful to have it behind me. Now to finish putting the rest of the boat back together.....
(Edited to augment and clarify my late-night hackings. Pics, of course, will follow once I get them sorted out and uploaded to the website.)
Last edited by Figment on Tue Apr 15, 2003 12:53 pm, edited 1 time in total.
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Guest
Here's a shot of some rotten wood, taken after the sawzall and shopvac had done their thing. It was like 5year old garden mulch.
Here's the nearly ADA-accessible head compartment, which became known as The Presidential Suite. (looking aft from the vberth)
and some pics of prepwork underway.
scrolling through these pics after I took them, I was a bit uncomfortable with the level of work, so I took the bad-weather opportunity to prep some more before installation. It seems like one really could just grind and grind forever.
A whole load of other photos will be on the website soon, but yahoo just isn't cooperating tonight.
Here's the port setee, all set up as the Mixing Station. Yes, that's my buddy Mr. Radiator off to the right.
And here's the starboard setee, which actually makes a pretty nice wet-out box once protected with some wax paper.
This closeup of some freshly laid tape (complete with the miracle Peel-Ply) shows a number of apparent dry spots and bubbles. After hours of poking, rolling, and rubbing, and attempted puncturing, I realized that the whitish spots are white on the substrate, and that the bubbles are just under the surface of the peel-ply, and therefore not structurally detrimental. I developed a "touch" for quickly eliminating these bubbles in later layups, taking better advantage of the peelply.
You can also see a chunk of the infamous foam fillet peeking out of the top.
Here's a shot of my personal little "upgrade", a.k.a. "deviation" from Alberg's design. Oh, yeah, and a pile of trim and scrap that some slob left up in the vberth.....
I don't know much about Carl Alberg beyond what I've learned from the NTA and NETA sites, but I'm guessing that he wasn't my size. I don't plan on using the vberth for much beyond storage, but dammit I want to be able to maneuver up there without the need to dislocate a shoulder every time I turn around! I couldn't let this opportunity slip by.
No, I'm not really concerned about compressive strength loss. The existing compression posts were dust for the bottom inch, so they weren't doing much anyway. Epoxy laminated curved posts, anchored to the bulkhead, will manage the buckling stress just fine.
Here's the nearly ADA-accessible head compartment, which became known as The Presidential Suite. (looking aft from the vberth)
and some pics of prepwork underway.
scrolling through these pics after I took them, I was a bit uncomfortable with the level of work, so I took the bad-weather opportunity to prep some more before installation. It seems like one really could just grind and grind forever.
A whole load of other photos will be on the website soon, but yahoo just isn't cooperating tonight.
Here's the port setee, all set up as the Mixing Station. Yes, that's my buddy Mr. Radiator off to the right.
And here's the starboard setee, which actually makes a pretty nice wet-out box once protected with some wax paper.
This closeup of some freshly laid tape (complete with the miracle Peel-Ply) shows a number of apparent dry spots and bubbles. After hours of poking, rolling, and rubbing, and attempted puncturing, I realized that the whitish spots are white on the substrate, and that the bubbles are just under the surface of the peel-ply, and therefore not structurally detrimental. I developed a "touch" for quickly eliminating these bubbles in later layups, taking better advantage of the peelply.
You can also see a chunk of the infamous foam fillet peeking out of the top.
Here's a shot of my personal little "upgrade", a.k.a. "deviation" from Alberg's design. Oh, yeah, and a pile of trim and scrap that some slob left up in the vberth.....
I don't know much about Carl Alberg beyond what I've learned from the NTA and NETA sites, but I'm guessing that he wasn't my size. I don't plan on using the vberth for much beyond storage, but dammit I want to be able to maneuver up there without the need to dislocate a shoulder every time I turn around! I couldn't let this opportunity slip by.
No, I'm not really concerned about compressive strength loss. The existing compression posts were dust for the bottom inch, so they weren't doing much anyway. Epoxy laminated curved posts, anchored to the bulkhead, will manage the buckling stress just fine.
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dasein668
- Boateg
- Posts: 1637
- Joined: Thu Apr 03, 2003 9:09 am
- Boat Name: Dasein
- Boat Type: Pearson Triton 668
- Location: Portland, Maine
- Contact:
Looks great! I really like the wider opening to the v-berth area too. I think you are right in thinking that the compression forces should be easily handled by laminated curved compression posts. Like your boat, 668s compression posts didn't actually make contact with sole or floors or anything else. They were about 1/2 inch short! The did, however, do a fine job of transfering the forces to the bulkheads, which seemed to handle the forces just fine.
I think we sometimes tend to overengineer things a bit... I know my new mast beam is ridiculously oversized for the forces encountered, but I guess it made me feel better at the time!
I think we sometimes tend to overengineer things a bit... I know my new mast beam is ridiculously oversized for the forces encountered, but I guess it made me feel better at the time!
Nathan
dasein668.com
dasein668.com
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Tim
- Shipwright Extraordinaire
- Posts: 5708
- Joined: Tue Apr 01, 2003 6:39 pm
- Boat Name: Glissando
- Boat Type: Pearson Triton
- Location: Whitefield, ME
- Contact:
Yeah, I like that "broadened" access to your vee berth too! As someone who isn't as (ahem) small as I should be, I share your feelings about the access!
On Glissando, I found that simply removing the ridiculous 2" thick door frame trim opened it up enough that I am now comfortable getting in and out. But your new bulkhead is even better!
Tim
On Glissando, I found that simply removing the ridiculous 2" thick door frame trim opened it up enough that I am now comfortable getting in and out. But your new bulkhead is even better!
Tim
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Figment
- Damned Because It's All Connected
- Posts: 2846
- Joined: Tue Apr 08, 2003 9:32 am
- Boat Name: Triton
- Boat Type: Grand Banks 42
- Location: L.I. Sound
Looking at it now, that is one AWFUL pic of the "access upgrade"!!!
I SWEAR, the curves are smooth, not segmented, and they're perfect mirror images of each other!
I think the light's playing strangely off of the CPES coating. I probably laid on one coat too many.
Nathan, I absolutely agree with your "overbuilding" comment. In reality, I think the path of forces goes from the mast step to the beam to the bulkhead to the hull. The "support posts" really behave primarily as bulkhead stiffeners. But still, I'm all in favor of Belts & Suspenders.
-Mike
I SWEAR, the curves are smooth, not segmented, and they're perfect mirror images of each other!
I think the light's playing strangely off of the CPES coating. I probably laid on one coat too many.
Nathan, I absolutely agree with your "overbuilding" comment. In reality, I think the path of forces goes from the mast step to the beam to the bulkhead to the hull. The "support posts" really behave primarily as bulkhead stiffeners. But still, I'm all in favor of Belts & Suspenders.
-Mike
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dasein668
- Boateg
- Posts: 1637
- Joined: Thu Apr 03, 2003 9:09 am
- Boat Name: Dasein
- Boat Type: Pearson Triton 668
- Location: Portland, Maine
- Contact:
Sure, sure. Mike, that's just what I tell everyone about my photos too! ;-PFigment wrote: I SWEAR, the curves are smooth, not segmented, and they're perfect mirror images of each other!
I think you are right on about the distribution of the mast compression forces. Not that I'm a naval architect or anything, but... based on practical experience, that seems to be true...
Nathan
dasein668.com
dasein668.com
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Figment
- Damned Because It's All Connected
- Posts: 2846
- Joined: Tue Apr 08, 2003 9:32 am
- Boat Name: Triton
- Boat Type: Grand Banks 42
- Location: L.I. Sound
With a bit more distance on the actual process, and a few weeks spent working with the results, I think this is worth adding.....
It was stupid, stupid, STUPID of me to cut the existing rotten bulkheads free the way I did.
I sawzalled through the shelf ends and vberth ends to free the bulkhead. Now I have these annoying little 1" gaps to fill.
I'd have been much better off if I had cut the bulkheads into sections around these connections. This would have eliminated this pesky task at hand, and would've provided some rather helpful guidance members when erecting the new bulkheads.
It was stupid, stupid, STUPID of me to cut the existing rotten bulkheads free the way I did.
I sawzalled through the shelf ends and vberth ends to free the bulkhead. Now I have these annoying little 1" gaps to fill.
I'd have been much better off if I had cut the bulkheads into sections around these connections. This would have eliminated this pesky task at hand, and would've provided some rather helpful guidance members when erecting the new bulkheads.