I bought yesterday 1994 Hobie Miracle.
Upon inspection I found:
1. bottom of the hulls stripped off gel coat at about 1” wide
2. crack about 2”-3” long on stripped bottom of port full
3. edges of daggerboard’s wells chipped a bit

Previous owner claims hulls don't get any water.
Should I put layer of fiberglass on stripped area and then apply gel coat on top of it? Should I open crack and fill it? What to use to fill chipped spots? Should I use polyester or epoxy resin?

Thanks,

Andrew



Edited by motogon on Mar 19, 2012 - 11:08 AM.

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Andrew
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A lot of great surfers were ruined by family and steady job.
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Since it's all on the bottom, and therefore likely to get little to zero uv exposure, I'd just use epoxy alone.

Hard to say without pics, but for #1 you can just make some fairing compound (or even marinetex) and make a wear strip about an inch wide. The beach will slowly work it off.

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Rob
OKC
Pile of Nacra parts..
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I'll try to take pictures tonite.

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Andrew
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A lot of great surfers were ruined by family and steady job.
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Here picture of the crack



chipped dagger board well



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Andrew
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A lot of great surfers were ruined by family and steady job.
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Where is the crack on the hull?

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Rob
OKC
Pile of Nacra parts..
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About 6" forward of dagger board well.

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Andrew
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A lot of great surfers were ruined by family and steady job.
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That boat needs a complete bottom job asap. It will not hold a full season sailing!
the epoxy is a good idea, but I usually do a thick layer of gelcoat and fair that.

How much did you give for the boat?

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Stefan, Denmark.
H14,H16,P16,P18,SC17,N5.8
Team StaySail
http://www.staysail.eu
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dichtbijzee

That boat needs a complete bottom job asap. It will not hold a full season sailing!
the epoxy is a good idea, but I usually do a thick layer of gelcoat and fair that.

Gelcoat will not fix that crack and chipped spots.

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Andrew
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A lot of great surfers were ruined by family and steady job.
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Chips should be partially filled with thickened polyester resin and topped with gelcoat.
Bottom job looks like it is wearing into the glass therefore I would put down a 0.75" layer of mat (Random fibers) then a 1" layer of fabric (woven) followed by a 1.25" layer of mat and a 1.5" layer of fabric. Paint on an extra coat of resin after the last layer of glass is in place and set. Use polyester resin for bottom job. Allow to cure and sand to shape using a belt sander, random orbital sander, and then hand sanding. Coat uniformly with gelcoat.
After you do the bottom job you need to get access inside the hull to fix that crack. I would puddle epoxy in the area of the crack and then start laying in layers of glass working from the center of the crack upeach side of the hull and out beyond the limits of the damage. Look at doing about 4 layers of glass (Mat, woven, mat, woven). Lay all of it up at one time so the layers of glass are not separated by large quantities of epoxy.

Rider_55

After you do the bottom job you need to get access inside the hull to fix that crack. I would puddle epoxy in the area of the crack and then start laying in layers of glass working from the center of the crack upeach side of the hull and out beyond the limits of the damage. Look at doing about 4 layers of glass (Mat, woven, mat, woven). Lay all of it up at one time so the layers of glass are not separated by large quantities of epoxy.

It is not accessible from inside (unless I cut hole on top of hull, and I don't think this is such good idea). Why not just remove all damaged fiberglass in crack area and fix it from outside? I can put few layers of fibeglass with same polyester resin.

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Andrew
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A lot of great surfers were ruined by family and steady job.
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Gotta respectfully, and quickly, disagree here.

1st, don't use csm with epoxy. You can get or make milled fibers if that's what you need. For the 'bottom job' an epoxy wear strip will be just fine and far faster and easier than laying glass and gel coating it. From glancing at the pics it looks like you can fill the dagger trunk chips w/ thickened epoxy -- quick and easy.

The fix for the crack depends on how weakened it is, and how close to sailing season you are.

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Rob
OKC
Pile of Nacra parts..
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motogon

It is not accessible from inside (unless I cut hole on top of hull, and I don't think this is such good idea). Why not just remove all damaged fiberglass in crack area and fix it from outside? I can put few layers of fiberglass with same polyester resin.

It is possible to make this repair effectively from the outside; however it will be much more difficult and labor intensive. You will have to cut out the bad glass and then taper the good glass back several inches so each successive layer of new glass bonds to old good glass. I typically sand back about 1 inch per layer tapering down to the full glass thickness at the damaged area. Sanding to restore shape and smoothness will be a long process. If you add an inspection port the tapering part of the repair is eliminated as everything is inside where appearance and smoothness are of no consequence.

yurdle

1st, don't use csm with epoxy. You can get or make milled fibers if that's what you need.

CSM is essentially just milled fibers pressed into mat form to ensure a random fiber orientation to eliminate the possibility of uni-axial reinforcement which mixed milled fibers may provide in a location where application will be difficult. I agree that CSM is typically not used with epoxy as delamination of mat on mat glass is not a problem as it is with polyester resin; however, working in a tight angular space with restricted access getting mat to conform to the sides can be problematic so I recommend the CSM be used as it conforms easily to irregular shapes when wetted out ensuring a good bond for the repair.

yurdle

For the 'bottom job' an epoxy wear strip will be just fine and far faster and easier than laying glass and gel coating it. From glancing at the pics it looks like you can fill the dagger trunk chips w/ thickened epoxy -- quick and easy.

Either way will work fine for function but IMHO unless the boat is to be painted, the poly and gelcoat combo is more aesthetically pleasing however it will require about 2 times the work.

West on CSM w/ epoxy

I've ignorantly tried it and had poor results. I'm sure it can be made to hold but it seems easier to me to buy some chopped/milled fibers if that's what you're going for.

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Rob
OKC
Pile of Nacra parts..
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BACKYARD BOAT REPAIR

Many incidents occur in which the catamaran gets banged, dinged, scratched and dragged up and down the beach, wearing the bottom off and thereby needing professional attention. Keel repair seems to be the most informative subject; the steps, tools and materials involved will also help to ~ repair other Fiberglass parts on the Catamaran. With a little technical help, you can attempt to reconstruct any damage occurred and be successful

Step one involves a trip to a local hardware store to purchase tools needed for the job. Presumably, you have already obtained the correct color of gel coat through your local marine supply or your local boat manufacturer. However, if it is not available there are substitutes that will work satisfactorily.

TOOLS NEEDED
1. Two 8” half-round. medium cut Stanley Surform blades.
2. Five sheets of 36 or 40 grit production sandpaper. Five sheets of 120 grit production sandpaper.
3. If you will be spraying a finish coat of gel coat you might also get. Three sheets of 220 wet or dry. Three sheets of 220 production paper. Two sheets of 400 wet or dry. Two sheets of 600 wet or dry. One can polishing compound. Fiberglass wax and polish.
4. One low-cost 1“ or 2” pure bristle brush (plastic bristles tend to dissolve in the resin).
5. Two small paper buckets size 16 oz. or 83 oz. (a flexible plastic bucket is actually better because it can be reused by removing the resin after it has hardened).
6. Empty coffee cans in which to clean the brushes.
7. Three or four stir sticks or tongue depressors.
8. One pair of scissors.
9. One razor knife or several single edge industrial quality razor blades.
10. One roll of 2” masking tape (one inch tape can be used).
11. One small piece of wet or sanding block 1“X3”XI2”.
12. Disposable light fitting latex gloves.
13, Small hand broom
14. Soft rubber squeegee, a medium-hard rubber squeegee used to work air bubbles out of the wet, saturated fiberglass cloth).
15. If you are planning to spray the gel coat try and find a spray propellant bomb with a glass canister.

The materials you will need are:

1. Resin - one half galIon
2. Catalyst - 3 ounces
3. Acetone - one gallon
4. Wax (surfacing agent) - 2 ounces
5. Fiberglass - 10 oz. or 11 oz. cloth ½ yard
6. Mat - 3/4 or ½ oz. ½ yard

Step two involves becoming familiar with the materials and chemicals and their purpose.

1. Resin
(Isothalic Polyester Laminating Resin)or General Purpose vinyl resin (GP)
This is the most commonly found resin anywhere.
2. Catalyst Methyl EthyI Keytone Peroxide, M .E.K .P.)
This is a hardener, when used in proper ratio with polyester resin produces polymerization (hardening or gelling).
3. Acetone
Acetone is a solvent. Use with extreme caution; it‘s highly flammable. Avoid contact with eyes.

4- Fiberglass
Ten and 12 ounce cloth are the most commonly used fiberglass cloth, although whatever is available will have to do. Heavier grades such a 5oz woven roving can be used, but beware of the resin draining out, which causes a dry laminate.
5. Glass Matting (Mat)
This is made of chopped-up Strands of fiberglass bonded together chemically in weights of ¾ ounces or 1 ½ ounces per sq. foot

With all of your materials at hand you can begin the actual bottom restoration. Naturally, there no great magic to resurfacing one's keel, the trick to this type of fiberglass repair is to try and be very neat. You cart count becoming messy at different stages.

Taking a few precautions in the beginning well insure good quality work.

1. Work in a welI ventilated area. Do not try to work outside in direct sunliglit. The sun will increase the gel time to 50% to 75%.
2. Keep out of the wind.
3. Protect the floor, resin gets pretty messy.


HULL PREPARATION

Start by cleaning the hull with acetone, especially if it is oily or dirty. Tape off the worn surface about 1/2" below the original gel coat line. Next, crease the tape in the middle; this will form a drape allowing the excess resin to run off in a stream and not down the side of the hull. After the hulls are taped off, take a sanding block with 36 grit sandpaper and level out the worn area, creating a clean feathering into the original gel coat. If there are any holes all the way through your hull this is an excellent time to repair them. Take and bevel the total circumference of the
hole. Slide in the hole a piece of very thin cardboard or milk jug with a string or fishing twine attached pull up against the hoIe and tie off to a pencil or stick that is laid across
the opening. Then, do a dry run making sure the cardboard fits properly. Mix a small one ounce batch of resin to glue the cardboard in place. When working with such a small batch of resin add the catalyst by the drops. This can be done by poking a little hole in a plastic container, or using a dip stick and allowing the catalyst to drop from the stick. It is difficult to weigh out small percentages for a small batch of resin. Assuming that a very short working time is needed, use about five drops of catalyst. This will give you ample time to glue the cardboard in place. Once
the cardboard is in place break off pieces of matting and mix with about 1/2 cup of resin (or more depending on the size of the hole). Mix into a mish-mash, catalyze and fill the depression slightly higher than the top of the hole to allow for shrinkage and to give you something
to sand. Use a surform rasp tool when freshly cured or crispy; this is preferred to as green. Now that the worn area is cleaned, taped, holes repaired and sanded, it is time to begin on some serious fiberglassing. Cut all the fiberglass cloth and mat into strips 1/2" wider that the worn surface. Try to overlap the tape by 1/2" or so to allow for a clean trim with the razor knife when cured. Lay up the resin a bit higher than the you need and use the surfaom tool to smooth it out, sand after till smooth. Gelcoat the repair(use a foam roller) and sand and polish. Good Luck!

TOOLS NEEDED:

*Two 8” half round medium cut Stanley Surform blades
*Five sheets of 36 or 40 grit sandpaper
*Five sheets of 120 grit sandpaper
*If you are going to spray a finish coat of gel coat you will need to get a pack of 220, 400, and *600 wet or dry 3M sandpaper.
*One can of polishing compound and can of wax
*3 or 4 cheap 1” or 2” pure bristle brushes

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Kenny Boudreaux
2010 C2 F18 USA 323
Goodall Design "Southern Area Rep"
Owner of Sailboxes.com
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