Hull work and barrier coating

[laika]

Originally Posted by minaret

Sure, it's easy enough to do. If you don't want to get into Kevlar or hybrids, a bit of carbon uni would really stiffen your stem. I always bury it under S-glass, so as not to have to grind on it. The materials complement each other anyway, stronger that way. Proset is a dream to glass with. If you are used to any other epoxy for laminating, you will be blown away. It's very expensive, about $100 a gallon. But you use so much less resin for a layup that it really does pay for itself. No post cure required, but I do it anyway. You can hand lam real nice with it, just be sure to peel ply. Even I might think you are a bit daft if you do the whole waterline like that! If you do glass the bottom, I can't imagine how an impregnator would help. If you wet out the glass before applying it to the hull, it's a nightmare. You'll have a huge wet layup fall on your head (been that guy, don't do it!). You apply a coat to the surface and let it solvent flash so it's a little tacky, then carefully place the dry glass. The sealer coat holds it in place while you wet out and squeegee. Glassing overhead sucks!


13.75 might be a bit much for a boat that size, I would use something lighter or it will be a pain to fair.

Thanks Minaret.

If you don't mind, I have a few more questions for the forum:

1. What layup material would you use for the purpose of added keel protection from hard groundings? Right now I'm thinking carbon fiber splayed out in strips from the bottom of the stem and spread a foot or two up to provide more area for dissipating impact.

2. How about material for collision protection at the waterline?

3. If cost is not an issue, do you think the Proset would be preferable to using standard West System as the base epoxy layers.

4. What brand peel-ply do you reach for?

I'm not opposed to kevlar, but seem to recall some bad juju by others in adding kevlar to the mix. A little more research suggests that kevlar can in fact be a real bear to repair properly later on if needed (say if a hard grounding actually did still do some damage with the kev layup there). I also seem to recall something about thermal expansion and contraction rates inherent in the different materials? I'm dubious to any real issue here given adequate bonding, but hey..

Carbon seems like the preferred material to work with. Maybe that's a happy medium between ease of use and strength. I am not familiar with any hybrids.

I "plan" on owning this boat for many many years and eventually traveling into higher latitudes.

Many thanks again to all for taking the time. Any criticisms also welcome

Ryan

[mitiempo]

I'm not an expert on different laminate materials but as I understand it carbon certainly adds strength but is not that abrasion resistant or for that matter very resistant to a good solid hit. Kevlar may be a better choice.

What is your opinion Minaret?

[s/v Jedi]

I have kevlar reinforcement at the turn of the bilge. However, this was done during original lay-up and it is under the outer layers.

Carbon works easy when I've used it but that wasn't often and just for things like spinnaker pole etc., never on a hull. It does not provide abrasion resistance IIRC, just stiffness (like if that's not enough )

[laika]

Thanks Mitiempo and Jedi. After more homework, I've decided carbon fiber would be a poor choice for me, as the main goal is impact resistance.

"[Carbon fiber] is very stiff and light, but it is also very brittle, has low impact resistance, and is not resilient. Unlike a fiberglass laminate, which bends and flexes quite a bit before breaking, a carbon-fiber laminate hardly flexes at all when subjected to severe loads. Up to a point this is good, but when it does reach its breaking point, carbon fails suddenly and catastrophically. It also fares poorly in collisions and other sudden point-loading situations."
FIBERGLASS BOATBUILDING: Creating a Laminate « www.yachtworld.com

My thinking right now is to go with clean, honest s-glass and biaxal/trixial for all applications on the hull exterior (under the new barrier coat).

I plan on:

-beefing up the skeg and rudder post joins (see pic below)
-wrapping the rudder with a layer of cloth
-wrapping a layer or two of s-glass around the stem
-a layer along where the two symmetrical hull halves were originally joined

I am still toying with the idea of using carbon, kevlar or twaron on the interior of the stem at and below the waterline (I have no hull liner and good access)...
E-glass and s-glass have good flexural and compressive properties. I really like the idea of coupling this with the high tensile strength of a kevlar or twaron on the interior layup. The idea would be the exterior hull acting as a kind of buffer to brace an impact while letting the stiffer, stronger fabric on the interior keep the overall matrix intact. That's the theory right now anyway.

Ryan

[laika]

An update here..I am back on the boat and have decided to go ahead with a second peel to remove the CSM and all the tiny delam zones still spotting the hull.



I had been beveling down some old thru-hull holes in prep to fill and was still finding tiny pockets of water seeping out of the deeper laminate as I ground down. I have begun consulting with the fiberglass guy here at the yard and he will be helping me as I move forward. The second peel will complicate things a bit more.

Since I am taking more material off with the second peel I will be replacing that material with some 1708 biaxal. Just for kicks, I also bought a roll of 6" kevlar tape which I will layup under the 1708 along the stem from the waterline all the way down to the keel. I plan on one 6" layer vertically wrapped along the leading edge followed by overlapping horizontal layers extending a foot or two astern. A 10yd roll of 5ounce 6" kevlar tape cost $87US and should be quite easy to work with.
Kevlar Tape, 17x17, Plain Weave, 5 oz/sq yd in stock | Fibre Glast

I also bought a small roll of 9ounce S-glass which I plan to use in multiple layers to beef up the rudder strut and skeg (namely where they join to the hull). It will be laid under the 1708.
Style 6781 S2-Glass fiberglass aerospace cloth in stock | Fibre Glast

I will use regular West System epoxy for all layups (w/ peel ply), then fair with West and 407 before many, many coats of gray Interprotect 2000. I have enlisted professional help for at least the first part of the layup.

The second peel will be taking place inside the next week and I will post some pics as things progress.

I am definitely going past what is necessary here, but I've gone this far The boat is worth it (and it's small).

As always, any advice or criticism welcome. Thanks to all.

Captain of the soon to be ice breaker "Muirgen",

Ryan

[minaret]

Wow, overkill! Your boat was over built from the factory, fix that sucker and go sailing (unless you prefer boat work, then find someone to pay you). The second peel will almost certainly only remove more chop matt, replace it with the same. Glass it back up with two or three layers of ounce and a half matt in poly with staggered butts. Then grind it and fair it in WEST, followed by six coats of 2000. If you've never glassed 1708 or faired heavy seams overhead, you'll thank me later. She'd be just like new, but with a barrier coat that works.

[laika]

Thanks Minaret. I do enjoy working on my boat but in fact prefer cruising to living in a boatyard Really appreciate the constructive criticism. Spurred on by your response, and a good heart to heart with the fiberglass guy here, I have decided that I am not going to move on the second peel after all.

I am still going to use the kevlar tape on the stem and do some light reinforcement with the s-glass. I will lay some cloth over the two hull halves that had previously cracked in a few places, and beef up the skeg and strut which have also seen some minor issues.

I had a moisture meter reading taken yesterday. The bottom of the keel read a bit wet, but it's been pretty soggy here in recent weeks. Everything else was good'n'dry. I have had her out for 6 months now, the first 3 of which I was washing her down twice a week. She is dry.

I'm excited to get this project done and will keep this thread updated as I move forward.

Still capt of the soon to be ice breaker "Muirgen",

Ryan

[Nicholson58]

Originally Posted by laika

An update here..I am back on the boat and have decided to go ahead with a second peel to remove the CSM and all the tiny delam zones still spotting the hull.



I had been beveling down some old thru-hull holes in prep to fill and was still finding tiny pockets of water seeping out of the deeper laminate as I ground down. I have begun consulting with the fiberglass guy here at the yard and he will be helping me as I move forward. The second peel will complicate things a bit more.

Since I am taking more material off with the second peel I will be replacing that material with some 1708 biaxal. Just for kicks, I also bought a roll of 6" kevlar tape which I will layup under the 1708 along the stem from the waterline all the way down to the keel. I plan on one 6" layer vertically wrapped along the leading edge followed by overlapping horizontal layers extending a foot or two astern. A 10yd roll of 5ounce 6" kevlar tape cost $87US and should be quite easy to work with.
Kevlar Tape, 17x17, Plain Weave, 5 oz/sq yd in stock | Fibre Glast

I also bought a small roll of 9ounce S-glass which I plan to use in multiple layers to beef up the rudder strut and skeg (namely where they join to the hull). It will be laid under the 1708.
Style 6781 S2-Glass fiberglass aerospace cloth in stock | Fibre Glast

I will use regular West System epoxy for all layups (w/ peel ply), then fair with West and 407 before many, many coats of gray Interprotect 2000. I have enlisted professional help for at least the first part of the layup.

The second peel will be taking place inside the next week and I will post some pics as things progress.

I am definitely going past what is necessary here, but I've gone this far The boat is worth it (and it's small).

As always, any advice or criticism welcome. Thanks to all.

Captain of the soon to be ice breaker "Muirgen",

Ryan

Save yourself some candy and check out US Composites 635 thin epoxy resin. I use no other at this point. They also sell glass and other stuff. Epoxy :Â*Epoxy Resins and Hardeners It easy to work with, long pot life, no blush. Clean up is with soap & water until it kicks. Love this stuff.

I have two layers of Kevlar on our 1984 Camper & Nicholson. It ALL weeps water along the fibers. Be careful on Kevlar. Make sure the resin will truely bond with it or it is only an unbonded net buried in your matrix. You might be better with more glass.

If you use epoxy as your resin, it will not blister again. Also, barrier coats - Interprotect 2000E. We applied 6 coats.

[colemj]

Originally Posted by minaret

Don't use alternating colors of 2000e. The reason is that white 2000 costs a lot more than grey. It is also much thinner, meaning you get less millage per coat.

I have used both white and grey, depending on what is available, and have never experienced either of these properties. Both cost exactly the same (google them - same price for both at west marine and defender), and both have had the exact same consistency/thickness/coverage (from actual experience and from reading the manufacturer's specifications for both).

Mark

[Nicholson58]

We also used the white & gray alternating layers. We noticed no variation in coverage and the cost was identical. It took a little less than a 4 gallon batch to cover our 58 foot hull X 16 beam. I think the LWL is about 48 feet & lots of keel.

[minaret]

We probably pay way less than you guys do, and for us we get less break on white 2000. Coverage is the same, millage is not. Just let two cans of base, one white one gray, sit on the shelf for too long and then mix them. You'll note the white only has about two inches of sediment settled out, while the gray has three or four. More solids, less solvent. Also, gray changes color when it dries, making white redundant unless you are color blind. They only sold gray for many years with no problems, till somebody had the brilliant idea that they'd sell more product with two colors. The main reason being that if you mix too much, which most people do, and you are only using one color, you can save the leftovers by keeping it in the freezer over night and mixing it in to the fresh batch the next day. But it won't make it two days, meaning you can't do this with alternating colors. Face it, white 2000 is a gimmick. Just my experience after coating hundreds of bottoms, not just one or two...

[colemj]

Their literature and directions state that the millage is the same for both colors (same number of coats to achieve a set thickness). The literature lists the VOC and solids contents as identical. The MSDS sheets are also identical.

If there is the difference you state, then Interlux seems wide open for a lawsuit.

There is a difference in solids contents and coverage and price between Interprotect 2000 HS (which only comes in grey) and Interprotect 2000e (which comes in white and grey). Perhaps you are confusing the two - but they are completely different products.

Mark

[minaret]

Originally Posted by colemj

Their literature and directions state that the millage is the same for both colors (same number of coats to achieve a set thickness). The literature lists the VOC and solids contents as identical. The MSDS sheets are also identical.

If there is the difference you state, then Interlux seems wide open for a lawsuit.

There is a difference in solids contents and coverage and price between Interprotect 2000 HS (which only comes in grey) and Interprotect 2000e (which comes in white and grey). Perhaps you are confusing the two - but they are completely different products.

Mark

No confusion here. 2000 high solids is for the California market, I've never even used it once. I'm sure if you tried to sue them they'd tell you the difference is due to the amount of pigmentation required for the different colors, an excuse I've heard before. Way to totally not address the main issue of wastage.

[colemj]

I'm sorry, but I am just going to have to go with the manufacturer's datasheet, the MSDS and my experience over your opinion on this one. I don't believe the company's lawyers are interested in trying to pull off the pigmentation argument because that one can be proven false very easily and cost them big time in court. It is doubtful a company as large as Interlux is taking such a huge risk trying to pull a scam this small in their overall market.

Occum's razor, you know…

BTW, what makes California's market so different that they need a higher solids product?

Mark

[hellosailor]

Someone remind me, what's a CSM?