1970 Coronado 15 Hull # 553 Repair, advice welcome!

Discussion in 'Sailboats' started by coronadoVT, Feb 9, 2018.

  1. Canracer
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    Canracer Senior Member

    I also don't think that removing the deck is a good idea. I think you'll need some cloth and some tape (nothing narrower than 6 inch.) You can find a yard or two of 10 ounce cloth for cheap. Buy this stuff on-line and safe a ton of money.

    I get that you want to reinforce the side stay backing plates, and that's a good idea. But that compression post should probably be addressed at some point (if not first, then a close second.)

    Can I make a suggestion? A reasonable thing to do first is remove all that old lumber from the centerboard slot forward. Sweep up and run the shop-vac around.
     
    Last edited: Sep 26, 2018
  2. coronadoVT
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    coronadoVT Junior Member

    I've found some good deals at fiberglass warehouse. It sounds like 6 inch tape is the way to go.
    I did forget to mention I have removed the compression post, and have measurements for a replacement.
    A big part of my problem here is a lack of fiberglass know-how. If I remove the 'fin' of thin wood which is also forward of the centerboard, can I just fiberglass a new one in place? Perhaps with a few strips of tape on each side?
    When you say I would need some cloth as well, where do you see using that as opposed to the tape?
    I like the idea of shop vac-ing the debris out for a clean workspace. I will set a goal to do this and put up new pictures this week!
    Thank you for the motivation, Canracer!
     
  3. Canracer
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    Canracer Senior Member

    That strip of wood under the old compression post should be replaced. It's rotted and no good. It has old fiberglass bonded to it. That glass is weak and it should pull right out (for the most part.)

    The fiberglass and epoxy work is no problem. Anyone can do it after a little practice. The exact type of cloth required is going to depend on the type of repairs you decide on.

    For example: In my hull, the long strip of wood (forefoot) was replaced with solid fiberglass. I think that's a good way to go. It's 7 layers of 10 oz cloth and 10 layers under the compression post. Looking back, I still think it was a good design and I'd add more layers if I was going build it again. It's very important to remove the old materials and sand the surfaces down clean (for strongest possible adhesion.)

    The glass cloth was put down between the stringers, and a grove was cut for the centerboard trunk. This is a stronger design than ending the cloth at the trunk. The stringers were installed on top of a heavy biax cloth. It was maybe 8 inches wide but it's not a "tape" (with sewn edges.) The biax was bought at a marine surplus store for almost nothing. I wanted to install the stringers (and they stiffen the hull) but I'm not convinced they were necessary (adding extra cloth to the center fiberglass plate would have been easier.)
    stringers2.jpg
     
    Last edited: Sep 26, 2018
  4. Canracer
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    Canracer Senior Member

    Just another note: Biax is easier to put down because it will conform to a radius. The weave of a tape is oriented at 90 degrees, making it's difficult to work with. Looking forward to seeing those post demolition photos.
     
  5. Canracer
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    Canracer Senior Member

    The strip of old wood and glass that's forward of the trunk and under the compression post is the "forefoot." A solid fiberglass forefoot makes a good foundation (and it'll never get wet and rot.)

    As mentioned earlier, I cut grooves into the cloth and extended the forefoot aft of the trunk. Here's an image of the front of the forefoot. (The bow bulkhead is too strong and I'm planning a rebuild.) The material is 10 ounce cloth. Don't order your cloth until you've decided on a design. If I built another one this way, I'd order heavier cloth because it builds up faster.

    Here's the fiberglass forefoot with compression post installed.
    forefoot1.jpg
     
    Last edited: Sep 26, 2018
  6. Canracer
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    Canracer Senior Member

    When the old forefoot is removed you'll find a brownish layer of solid resin. Pull away all loose glass and sand down the surfaces. Here you can see the stringers installed on heavy biax, filleted, and covered with 10 ounce cloth. At this point I started to lay up the new forefoot. To make it more solid, also use woven roving and heavy biax (10 ounce is too light and it takes a long time to build up thickness.)
    forefoot2.jpg
     
    Last edited: Sep 26, 2018
  7. Canracer
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    Canracer Senior Member

    I've ordered from this company a few times. I like the web site, the service, and the product. It's also significantly less expensive than the company you previously mentioned. If you ordered the 1/2 gallon epoxy kit (resin and hardener,) there's a good chance you'd never run out. The 1 quart kit should easily be enough to build the forefoot and maybe more. (The "medium" hardener would be ok this time of year but you might consider "fast" if your working in a cool environment.) Because of the length of the forefoot, you'll want cloth in 2 yard lengths.

    www.uscomposites.com
    epoxy1.jpg
     
    Last edited: Sep 26, 2018
  8. coronadoVT
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    coronadoVT Junior Member

    Hi Canracer,
    Thanks for the link. I have done some reading about fiberglass and epoxy, and you are right that this website is a great source!
    My understanding is that I could order the half gallon kit of 3:1 Medium epoxy kit, some 6 inch tape, and 2 yards of 10 oz biaxial cloth, and with this I should be able to reglass the forefoot, glass in the new compression post, and tab in the bulkhead.
    I really appreciate your support; this is something I have wanted to learn for a while now, and I can actually see it taking shape!
    Would you recommend getting the cloth in a certain width?
    When I remove the wooden 'fin' on the forefoot, the goal is to get down to the subsurface, or the light brown epoxy layer below, right? I would then lay some cloth down, with epoxy resin, going back on either side of the centerboard trunk, and on top of this, mount the compression post?
    Thanks for your encouragement and support.
     
  9. coronadoVT
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    coronadoVT Junior Member

    WOW! These prices are crazy. I thought the other site was cheap, this is a wonderful resource. I will make an order after work today.
    Which bi-axial cloth would you recommend? I'm looking at the 45 Degree angle, 17 oz, with one layer of 3/4 oz mat, in 36 inch width.
     
  10. Canracer
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    Canracer Senior Member

    The biax should be the 45 degree with no mat. Mat is tricky because some of it is designed to only work with styrene based polyester resins. You don't need mat. Two yards of 17 ounce cloth, two yards of 10 ounce cloth, two yards of the heavy biax should make for a nice inventory. Stuff you don't need immediately will be useful down the road. You should also order mixing cups and sticks (5 cups and 10 sticks.) Not little cups, but the small buckets (mine hold 14 ounces.) Also one of those rollers that's designed to move resin through the cloth and take out air pockets. US Composites calls it a fiberglass detail roller. A 3" roller would work fine.
     
  11. coronadoVT
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    coronadoVT Junior Member

    Ok, here is my order as prepared, do you think I missed anything?
    1. 45 degree, 17 oz, no mat, biaxial cloth, 50 inch: 2 yards
    2. 18 oz E glass cloth, 2 yards
    3. 10 oz E glass cloth, 2 yards
    4. 1/2 gal epoxy kit, 635 MEDIUM, with hardener
    5. mixing sticks and containers
    6. brush
    7. roller
    8. squeege
    9. 4 inch tape, 4 yards
    10. 6 inch tape, 6 yards
    All of this is just over $100, so I feel like I will have a good stock to learn the process and reinforce the forefoot, install a new compression post, reinforce under the chainplates, and re tab in the bulkhead (using tape).
     
  12. Canracer
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    Canracer Senior Member

    I found that tape was hard to work with. Any glass that you need you could cut from the cloth. But the order looks good.
     
  13. Canracer
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    Canracer Senior Member

    I just remembered something. You will want to get a respirator mask. Please don't sand or grind fiberglass without one. A good quality 3M mask can be found at any big box hardware store and on-line. Also safety glasses. If you plan to use power tools,,,ear protection.

    Latex gloves are a must, lots of paper towels, and alcohol as a cleaning solvent.
     
  14. Canracer
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    Canracer Senior Member

    Did you order already? Forgot to mention epoxy fillers. You'll need some silica. On the US Composites site they call it Aerosil-Cabosil. You will also want a filler for fairing; this is called Phenolic Microballoons.
     

  15. Canracer
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    Canracer Senior Member

    Check out these sailors as the do some epoxy work.

     
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