> Hi all,

> I need advice on how to repair a 3' by 1' section of glass. It seems to me
> that the epoxy never bonded to the hull as the glass had delaminated and
> came off fairly easy.

Did you build this boat or buy it? It sounds like this is a second-hand craft and you do not have a good history on it.

Problems like this are more common with polyester resin than with epoxy, and that is my best guess about this. Some woods (red cedar is one) have oils in them which keep the polyester resin from forming a strong bond. I understand white cedar was the prefered wood when polyester was the primary resin used for this type of construction. With red cedar the wood had to be primed or sealed with a lacquer or similar finish before applyling the resin and glass.

If the original boat was built with epoxy and there is only one bad area. patch it now and use the boat. If you avoid rocks you may never have to patch the thing again.

If it is polyester you can expect to make more repairs like this, but perhaps you will only need to do them once every year or two. In this case, you patch now, and you paddle the boat for 1 to 5 years, applying seasonal patches. Save your money until you can afford enough sandpaper, glass and resin to redo the boat. There is no reason to rush this.

Epoxy sticks to the polyester that is already there (if it is polyester) and it also sticks to epoxy, so by using epoxy for the patch you are doing the right thing, either way.

> Should I use a 'seal coat'?

Probably a waste of time for such a small area. If the previous material was epoxy then your sanding will not remove the resin which has already soaked in and sealed the wood (thus serving as your seal coat). If the previous material was polyester then it never soaked in very deeply and your sanding will open the pores in the wood, allowing your resin to saok in with your first coat. Because of the size, you should be able to monitor the first coat easily to avoid any `starved' areas.

> Should I use the 'wet
> method' to apply the glass as decribed in the West System Manual? Should I
> use the 'dry method', which must be how the boat was constructed?

Can't help you here as I am unfamiliar with both terms.

> Any advice on over lapping the glass? Thanks in advance.

Remove the glas that is not adhering. Sand back to `good' areas. If the area to be patched is roughly rectangular, the corners of the repair should be a bit less noticeable if they are rounded, rather than square. Gently sand the `good' glass over an area 2 to 3 inches wide bordering the bare spot. Taper this, or `feather' it so that the glass coating is full thickness when it is 3 inches from the patch, and 1/2 of its thickness at an inch to 1.5 inches from the bare spot. It you rub your finger over the border between bare spot and and where the fiberglass starts, you should not feel any bulges or bumps.

Cut your patch material to overlap the bare spot by at least 3 inches on all sides. This should match up with the outside perimeter of the area you have feather sanded. If you go a bit larger (even up to an inch more) you are doing OK. Try to not go smaller.

You can paint a coat of resin on the area with a foam brush and then lay the glass cloth on. The resin is sticky enough to hold the cloth while you add more resin to the outside. Work this in with the brush and add a bit to any areas where the resin seems to be soaking into the wood. Go gently. Expect to see the weave of the fabric. It should be transparent, not white. Later coats of resin will smooth this. If you put too much on now it will just drip and run.

Once you start painting on the resin you will hide the edges of your repair, which can make aligning the cloth for the patch a bit difficult. I put dabs of masking tape on the hull just outside the sanding line to define the area I am patching. After the cloth is mostly in place if any of it touches the tape, i either shif the entire patch, or just lift the edge of the patch, peel off the tape, and let the glass go back to covering that area. Never had a problem with any trapped residue of adhesive from the tape.

An alternate way to align the cloth for the patch is to use dabs of masking tape to hold the dry cloth over the repair area before you saturate it with resin. Pull off the tape as you get to each piece. Don't use more tape than the minimum to hold the cloth on. (if you are good, 5 inches TOTAL should do!) You can use a foam brush or a squeegee to work in the resin.

Either way, after the resin has set you are going to sand the center of the patch lightly, and the outside edges more aggresively. Again, you want to create a taper over the outside 3 inches, so that the very outside edge of the patch is of negligible thickness, but the patch approaches full thickness at the point of where it covers the (previously) bare wood.

Use a new foam brush to put on another layer of resin, which may or may not fill the weave of the cloth in your patch. After this sets, gently sand off any drips and runs, and apply a third coat. Sand smooth. (Three coats should do the job, but if you have been stingy you may need a thin 4th coat.) Now would be a good time to lightly sand the rest of the boat and cover it all with a varnish that has a UV inhibitor and call it quits.

If you could look at a cross section of the patch you would see that the old material was sanded in a ramp-like shape, gently going from full thickness to nothing. Meanwhile, the patch material was sanded flat, forming a matching pattern to that ramp, with the excess material cut off of the top.

George likes to use thin fabric and put on several layers. He builds strong boats this way, and believes this is the stronges way to patch them. It probably is. Others, including me, use a single layer of 4 ounce or 6 ounce material for patches, unless we can see that the older material was thicker, in which case we try to match it. Most -- probably all -- older boats used a single layer of glass cloth over most of the boat, with some boats having a double layer (for scratch resistance) on the bottom of the hull. In the old days, when the varieties of glass cloth available to amateurs was more limited, and more expensive, multiple layers were not even thought of. Using multiple layers to make a patch that is stronger than the original is certainly possible, and will not be much more expensive.

If you are using 3 layers of 2 or 3 ounce fabric, you can cut them to different sizes. The bottom layer (that which rests on the bare wood) is only an inch larger than the bare spot. The next layer is larger by one inch on all sides, and the top layer is 2 inches larger than the first ( an inch larger than the middle) This overlapping of edges MAY make it a bit easier to sand in, as only the top layer has to have a feather edge -- and that will be much narrower. OR, you can cut all three pieces of fabric to the same size and treat them as if they were one thick piece. Either way, you can put down a coat of resin first and then lay them down together, (or put down one, and immediately put on the 2nd and then the third) saturating them all with your first coat of resin. Or, you can tape them in place and apply the resin with a squeegee. If you do this, you'll use a bit more tape. Be sure to get ALL the pieces out before the resin sets up. After that, sand and finish as described in the first part.

If you go with the multi-layered fabric method for repair, then when the time comes to redo the hull you`ll be able to see how well that portion has held up. If it suits you, then redo the whole hull with 3 layers of 2 to 3 ounce material at that time. The resin cost for three layers of 2 ounce fabric should be the same as for one layer of 6 ounce clath, but the fabric itself will be more expensive as you must buy more yards of it. You should have a few years to save your pennies for the additional costs.

The patched area may be a different color (probably lighter) than the rest of the boat. If this patch is above the water line, or in a perticularly visible spot, consider turning it into an art element. If you use the lighter color of the mostly rectangular area as a back ground, you can make a design out of a dark-colored wood veneer and stick the design in that area. It will look like a picture frame surrounding your art, and could be visually striking.

Hope this helps Paul Jacobson