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Thread: stripping the bottom

  1. #16
    Join Date
    Apr 2002
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    ebb,

    From your article, " Many of the older polyester boats which did not blister, but showed crazing, probably were made of highly leachable polyesters. The group at the University of Rhode Island has developed a method for increasing the leachability of WSM from composites and thereby preventing blister formation. What is not known, at this point, is the effect of the porous gel coat on the long term strength properties of the polyester. This is a subject on which research is continuing."

    So the good news is I think my hull has the crazing associated with leaching, so won't get blisters. The unknown or potentially bad news is, the boat may eventually melt away like an Ice Cube on a hot Texas day!

    Kent

  2. #17
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    When I rehabed Solsken, I used a 1/8" Dremel routing tool bit to rout out all the above water cracks - a big job. What I found was that once I went through the gel coat, the glass was very solid, so that if the cracks were caused by WSM, it didn't appear to have any effect on the underlying glass.

    Having said that, I don't know if I could have seen a hairline crack in the glass resin itself, but if there were leaching and/or blistering, I would have seen that, I presume.

  3. #18
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    Long live fiberglass!

    Doctors Rockett and Rose have bestowed an unexpected mortality on our Ariel Commanders, haven't they? Now, like their skippers, the old gals have an actual life span too. We can deny our aging problems together - porosity, cracks, sagging and chemical reactions. We can try to extend both with good potions, cosmetics, plastic surgery and please with pricey new clothes and trinkets and lots of attention.

    I do feel that much more tender toward the little beast (or is it paranoia?) now that I can just make out her heart. When I pat her flank she quivers as she did when she first entered the water decades ago! Hope she's not under the weather today.
    Last edited by ebb; 05-04-2004 at 07:00 AM.

  4. #19
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    Aside from all the workaday problems and contaminations in the laminating process, there are only two kinds of polyester used for boats. The good - iso. And the bad - ortho. It's completely obvious from the way Ariel/Commanders have prevailed that Pearson used the best isophthalic polyester resin available for the hand layups of the hull, deck and liner - and the gel coat. The material is proof of its superior chemical stability and flexibility.

    All of our shrinking days are long gone. Probably nearly all of our resin swelling days too. IMHO all of our problems with the gel coat are mechanical rather than chemical. and related to age. Cracks appear in or at corners. or where fastenings were cinched, or where the coat was built up too thick. Or where too much was going on.

    Wouldn't you say that after 45 years Ariel/Commanders are pretty inert? The only worry perhaps is whether the resin is going to let go of the fabric as the boat is pulled and pushed and punched by water and wind. Any tests on the aging of organic resins since that paper was written 20 years ago?

    If our old resin was highly leachable, I'ld say that whatever wanted to leach was leached.

    What we need is a true penetrating agent that would soak like water into the porous carapace of hull and deck and harden up in the interstices with fresh new rubbery strength. A penetrating anti-aging cream that really worked.
    Last edited by ebb; 05-04-2004 at 07:17 PM.

  5. #20
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    Have a question in regard to fiberglass aging. My recollection is that for fiberglass boats that are over 20 years old, insurance companies don't (or didn't) want to insure them - i.e. insurance was difficult to get. I remember one insurance company dropping insurance on my boat because of its age. Is this still true, and why? Currently I have boat US insurance and there appeared to be no problems with aging, other than they wanted to make sure the boat wouldn't sink when it first went into the water.

    My understanding had been that the insurance companies didn't want to risk aging fiberglass.

  6. #21
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    Lloyds is the only insurance company that will take on any risk. All the others bet on sure things only. BoatUS must base their willingness to insure old boats on plastics industry and government records and tests, wouldn't you guess? I believe no survey of durability has shown any structural degradation of marine plastics composits from the 60s, with possible exception of sandwich panels. But then I'm no researcher.

    Somebody at BoatUS has factored into their risk accesment that first decade fiberglass boats are cool. Maybe there are some old tanks and barges still in service, but I bet the military has long since obsoleted their unfashionable craft. No records kept any more. Accelerated aging test procedures on recent composites can't have any relevance to our historical resins.

    So who has done any surveys or testing of our PORUS glass boats? Even to find out if any chemical reactions are still occuring under the gelcoat? That 20 year old paper refered to here is the only one that even mentions "HIGHLY LEACHABLE POLYESTERS" that I've casually run into on the net. Maybe that phrase is a highly imaginative invention of a technician filling in unanswered questions at the end of controversial report.

    I sure would like to know if any more resin is leaving my boat. So would BoatUS no doubt. In the meantime, and remembering that Ariels and Commanders have evidently made it safely across oceans, and Tritons circumnavigated, epoxy barrier coats and lpu is the way to go.

    I remember in the past West Marine was totally uninterested in insuring old boats. Now that WM has gobbled up BoatUS. I hope that insurance for the rest of us remains available.
    Last edited by ebb; 05-08-2004 at 07:37 AM.

  7. #22
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    I found it interesting that when I reinsured my boat after being out of the water 22 years, all that Boat US needed, as I recall (other than registration procedural stuff) was a photograph of the boat in its current condition.

    My assumption (and you know what that means) has been that their concern was whether the boat had been maintained,their principal concern with an older boat being that someone is not trying to insure a beat up clunker to sink the boat and collect insurance. In other words, if the boat shows TLC, they will put their insurance on the line. Plus, for an old boat, the amount is not that mch. So, what do you think about my assumption?

  8. #23
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    After you get done stripping the hull....

    After you get done stripping the hull.... how much bottom paint did it take to re-paint it?


    s/v 'Faith'

    1964 Ariel #226
    Link to our travels on Sailfar.net

  9. #24
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    Jan 2007
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    I am in the process of removing all the bottom paint on my boat. I think there are at least eight layers!!

    I am going down to the old gel coat. Before I bottom paint should I barrier coat? The gel coat appears pitted and crazed.

    If a barrier coat is necessary does anyone have any recommendations as to what a good product would be?

    Thanks for any help!

    Andrew

  10. #25
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    Quote Originally Posted by Westgate View Post
    Before I bottom paint should I barrier coat?
    Not unless you're ready to leave the boat out of the water for three months or more. Manual has a section on the procedure and the need to "vent" the water from the hull first.

  11. #26
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    whats on your bottom?

    Andrew,
    Most of us are VERY interested in what condition you ultimately find your gelcoat on the bottom. It's going to be somewhat different than the topsides.

    Others here, and myself, have chronicled what we found. My official surveyor at the time I bought my Ariel found some blisters that miraculously disappeared when my eight layers of paint were removed. My chemical removal method and some vigorous scrubbing left color in the imperfections of the gelcoat. A lot of recorded history, plus a big badly repaired booboo by the factory in the form of a hole in the bottom of the keel!

    But generally the gelcoat below the waterline on 338 had none of the modern blisters caused by poor materials and lousey production methods of many boats made in the '70s, '80s, etc.

    Any cracking should be forensiced for deterioration of the laminate. Star cracks might hide some delamination. Should be ground out and filled the same way an old through-hull is closed. I believe it is safe to assume that small cracks exist in the gelcoat alone and do not enter the fiberglass.
    Suspicious areas should be sounded with a ballpeen hammer for deadness.

    Revealing what is under the layers of bottom paint is a good thing, not only for you, suh, but for all us lazier owners as well!!!

    If you are filling an imperfection with epoxy gel you can add some unversal white and forge an almost as-good-as gelcoat repair.

    Barrier coating is well covered here in the Forums. I think it should be done to keep moisture from migrating into the polyester laminate. I can't remember what I used, but I chose a white one so that when paint was removed again it would be an indicator. When you look for a coating it's maybe better to look for a designated barrier coat because gelcoat is sometimes hard to get a coating to stick to even after sanding. Has to do with the filler in the gelcoat.
    BUT on Little Gull, I ended up with multiple coats of low viscosity epoxy with powdered copper mixed in. (epoxyproducts.com) I consider these (8?) coats to be also 'barrier' and would not remove them. I also doubt that coppering the bottom this way will do what Trinidad (blue, green, red, and black) can do, and will roll on bottom before launching.
    __________________________________________________ ___________________________________________
    It is the nature of polyester gelcoat to crack. That is what it does.
    If the cracks are tight, you can't pry off any chips, begin neutering the cracks with two part 100% solids no blush epoxy laminating resin. The stuff is runny, you want to jab the resin into the cracks with the brush. Cut the bristles short if need be. This works on deck also.
    I personally would then wipe the areas clean with alcohol dampened, barely damp, paper/rags. Leave the resin to harden or start to set up in the crazing. Then fill with 407 and epoxy paste. 407 will give you a chocolate color filler. Use a plastic applicator so you leave little build-up of compound behind on the repair to make next sanding easy.
    Heavily sand the whole underbody gelcoat in prep. Most barrier coats are systems, so there will probably be a primer. Some barrier primer systems have a high-built sanding one, so that after the final 120 grit bruhaha the barrier will roll on smooth as silk! imco.
    It is, of course, entirely OK to buy a high-end barrier epoxy and apply it without a primer. It is in the nature of the coating. Most coatings are meant to do a job without fuss, like a special coating for leaky water tanks. That's what was used on Little Gull's bottom. The copper hard coats were put on top of that.
    Much satisfaction and relief when done.
    Last edited by ebb; 03-15-2008 at 01:33 PM.

  12. #27
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    My bottom looks ugly!

    After 10 hours on the sanders/grinders we made a bit more progress. Bought a new PorterCable RO sander for the job and it gave up the ghost at 4PM today! Box store trade in tomorrow AM!! Forgot to take pics but will do so tomorrow. The topsides look pretty good so far. There are a few cracks but nothing major yet. The bottom is another story. Heavily cracked gel coat. Crazed spiders everywhere! We're talking crack crazed arachnids! I few pieces of gel coat missing here and there.

    Very happy that I am doing this. After the job is done I'll know what's there and be more confident in the hull. I too have a "bad" repair job in the lower leading edge of the keel. Looks to me like somebody hit something. I'll photo it tomorrow. Also uncovered the old propeller shaft patch up.

    Drilled a few holes -very close to the bottom of the keel just forward of the shoe. Solid thru-out no hollow space. I don't have a void there as it was dug out and incorporated into the bilge (I think). I drilled a hole into the bilge to confirm this theory!!! There is a weep of salt water coming out of these lower holes. Not more than a drop, drop kind of flow but water is there. "My keel is shedding those salty tears!". Looks like it might be coming out of the laminate but really hard to tell. Bilge is bone dry so not coming from there. I suppose that there could be a void more forward?

    We have decided that the hull really needs a barrier coat so we are going to leave it out for the summer. It kills me to do this as I'll miss some great spring sailing but I'd rather have a solid water tight boat. My job is really busy during the summer so no sailing then anyway. Will also be some piece of mind having Arthur on the hard during hurricane season. Thankfully we now switch to the monthly hard time rate which is much more reasonable. I was totally stressing out about getting everything done in two weeks, so I feel better that I can spend a bit more time planning and executing the tasks that need to be done. Our plan is to take the whole boat down to gel coat

    We may tackle the decks..............may being the opperative word.

    Looking forward to the longboard baby!!

    Andrew
    Last edited by Westgate; 03-16-2008 at 04:24 AM. Reason: errors

  13. #28
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    Here are a few shots of the hull. Still not completely stripped but we did make some progress this w-end. I figure we are over half way so that's encouraging. I will be very happy when this part is done!

    Also posted a few close ups of the hull. Photos aren't great but gives you and idea. Topsides look good. Bottom shows signs of crazing and a few bigger cracks. The gel coat on the keel is badly pitted. The old boot strip groove is also visible. All these sins from the past were hidden under paint. I closely inspected the hull prior to peeling and none of this was evident.

    Andrew
    Attached Images          

  14. #29
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    Andrew,
    No surprises there in the photos.

    Much said eleswhere here about water in the hollow spaces where the ballast keel is.
    Drill holes and get it drained, if you haven't It will help dry the hull out for coating.

  15. #30
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    Andrew

    nice to see a bottom that hasn't suffered from bondo repairs. a little thickend epoxy, some long boarding and she'll be as good as new.

    cheers,
    bill@ariel231

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