John Burritt

Remember that the whole boat will have multiple coats of epoxy to keep it as waterproof as possible. You don't need to worry about defined edges. The trick is to watch for epoxy runs and wipe them up before the epoxy hardens. Wet's much easier to clean up than dry. We've all learned that the hard way. Some of us repeatedly. Maybe this is preaching to the choir, but also remember epoxy gets warmer and more fluid as it cures, so you need to check back periodically for new runs. Not knowing your experience w/ epoxy, thought I'd mention wetting & coating w/ unthickened epoxy vs. gluing & filleting w/ thickened epoxy. Have fun.

Welcome. Don't be bashful should questions arise re: the spindrift. We're always glad to provide a variety of answers, even to simple questions.

Install the doubler before doing the side seams. Locking up the side seams first would prevent the bottom from assuming the proper shape w/ the doubler. Yes, installing the doubler uses a lot of epoxy. As you say, 1st wet both surfaces (after you've scored the underside of the doubler). You should be able to apply thickened epoxy only to one surface - I'd do the boat bottom - as long as you get a good reasonably thick even coat. This time you're looking for "runny mayonnaise" rather than the "thick peanut butter" you use to make fillets. Be sure the surface is well coated and you don't scrape it off when you put in the doubler. Also be sure that the edges have squeeze-out ALL AROUND so you don't leave gaps where water could get underneath later.

The doubler fitted to the bottom of the boat should just clear the ties on the side seams. Glue the doubler in place. Then put SMALL fillets between the ties - small enough that they won't interfere w/ the regular fillet & "between" so you don't glue the ties in.. Once these harden, the ties can be removed. Then fillet and tape the inside seams. Now you can either turn the boat over; round the outside of the seam; and tape it. No filleting on the outside - just some thickened epoxy if you have some gaps to fill. Actually, yuou can continue working on the inside of the boat and do the outside seams later.

John - What epoxy? Aren't all tools a mottled brown color?

Be really nice to your mother-in-law. You may get some real gems.

The OB 20 is in eastern North Carolina not far from New Bern. Graham can get you in touch w/ the owner/bulder.

Just to throw another complication into the decision - have you considered a Core Sound 15?

I'd glue the gunwales/inwales & breasthooks before I did the doubler. Also pull the beam to the proper width. This pull the boat into the proper shape. Then fit the doubler, forcing it against the bottom to maintain that shape. You need to bridge across the gunwales so that the temporary props hold the doubler in place while the epoxy sets. Support the hull at each end beyond where the doubler fits so you don't set a flat spot in the hull. Fillet & tape the inside seams before you do the outside. The outside of the bottom/side joint needs to be rounded & faired before it is taped. You can't do this before the seam ties are removed. Ties can't come out until the seams are secure on the inside.

Don't have a set of CS20 plans. Should be a drawing of a side view of the assembled hull w/ the displacement waterline marked on it. You'll probably want to mark your actual waterline a bit above that so that the bottom paint shows all around even when the boat is a bit out of trim. If all else fails, contact Graham for the specific measurement. Actually, once the boat is leveled, you can put the line anywhere you want it - keeping it level.

Set the boat on its building jig/trailer/whatever on a level surface. Be sure its level side to side. Elevate/lower the bow so that it is 10 5/8" higher from the floor than the corner of the transom. Now the boat's level. Pick your height for the waterline and mark it along both sides of the boat. There are numerous ways of doing this, including measuring vertically up from the flat floor. Not sure I'd try the method described in your quote.

Check the beam measurement midships. Clamp or spread as necessary to match the plan dimension. Then check the fit of the breasthooks you've cut. Use a bevel gauge to determine the actual angle for your boat. Check it at both ends of the breasthook - could well vary a bit. Use the bevel gauge to mark the cut angles at each end. Rough in a cut line on the underside and plane to the line, checking your fit periodically until you're satisfied w/ the fit. Don't count on the shapes/angles being the same from side to side or end to end.

Cut a piece of pvc pipe at least an inch wide. Then split one side of it. See how hard it is to spread. If its not fairly hard, its not wide enough. The trick is to cut it so you can just spread it to fit over what you're clamping. Be sure they close all the gaps when you're clamping. Might want to use some c-clamps in critical places.

The epoxy isn't going to burst into flames, although it may give off smoky fumes. Just set the cup on something non-flammible and wait for it to cool off. A metal cup (juice can) won't melt, but could get hot enough to burn your fingers. A plastic cup can melt, which can make a mess. The up side of this is that as soon as the epoxy starts spreading out, it will cool down much more quickly. If you're coating a surface and the cup starts getting warm, pour the epoxy out and spread it around. Working time is greatly extended. Using a slow hardener, there isn't much chance of heat buildup this time of year unless you mix a cup and set it aside and do something else. In short, the bigger the surface the epoxy is on, the slower the heat buildup. Fillets and glue-ups may get a little warm, but not hot.

If you leave mixed epoxy in a cup too long it will get so hot it will start to smoke. Something you should watch for when spreading unthickened epoxy is that if the consistency gets thicker and the cup gets warmer, stop using it. It will be too far gone to spread properly. Back to filling and regluing the gaps midship, I'd leave those until I had the gunwales on and the shear fair. When gluing on the butt blocks, pre-wet both surfaces w/ unthickened epoxy. Then apply thickened epoxy to one surface in a thin, even coat. Use enough that you get squeeze-out when you clamp it in place. Clean up the excess while its still wet. Then go back after a bit and check for more squeeze-out. Clamping is a balance between tight enough to firmly seat the piece and being too tight and squeezing out all the epoxy.

Several issues - the grey (white?) areas in the glass tape show where there are air voids between the tape and the wood - no bond. The marvels of gap-filling epoxy are marvelous only when you add thickener. Gap-filling is like filleting - no thickener, the epoxy drains out when it gets warm curing. The midship joints typically are joined by a plywood butt block glued to the inside. The grain in the plywood should run across the joint and the block should run past the joint 8 times the thickness of the hull sides EACH way w/ the grain in the block running fore & aft. You can cut the butt block to fit under the inwale. Which brings up that the gunwales & inwales can be glued in place before that butt joint is installed. Whatever wood you use for the gunwales needs to be clear - no knots - and as straight-grained as possible. Poplar should work - I know pine will. Clamp or screw a STRAIGHT fence to your wood as a guide for your saw. If you don't have a long work bench, a 2" thick piece of foam board make a good sacrificial base for cutting and protects the saw blade (use the circular saw if you do this.) Unless your board is longer than needed for the gunwales, you'll have to epoxy (thickened epoxy) two pieces together using an 8:1 scarf. Be sure to keep the joints straight in both planes while you're gluing them. Rough cut and glue up both your inwales and outwales at the same time. When fitting them in the boat flip them so that the inside and outside joints are not opposite each other.

Could be either a flat spot if you're squeezing, (or a bump if you're spreading) the shear to meet the design width. Its a disruption of the fair curve.

Ditto Jeff's question about 4 fishing in an S12. The construction techniques for a CS are the same as a spindrift (or very similar) - the parts are bigger and a bit more of them. For 4 people, I think I'd talk to Graham about a CS kit - all precut. Maybe you can trade in the S12 plans.

Cut the outside gunwales a bit long - quite a bit if you're not sure of the length. Clamp the end of one gunwale just a wee bit past the bow, but not enough so that it will interfere w/ the other side - clamp it along the shear and let it run wild past the stern. Do the opposite on the other side of the boat - just fits inside the first gunwale, clamp it along the other shear, and let it run past the bow. This should pull the boat into a fair shape at the shear. Check the beam dimension against the plans and compress/spread if necessary. Use several clamps spread out do you don't create a hard spot in the shear. I'd also cut the breast hooks as per the plans and fit (not glue) them into the bow and stern. These also will help give the proper shape. Now see how the mid-ship side joints are fitting. If they aren't tight together, they should be real close w/ the ends parallel. Adjust the ties on the bottom/side seams for a good fit. Once everything looks good, you'll be ready to think about gluing. (If you haven't already figured it out, its real hard to end up w/ too many clamps.)

ChrisObee - no disagreement w/ your comments. I'm concerned that the boat be pulled into shape before all the seams are glued. Otherwise it may not be fair.

You need to at least spring the gunwales around the shear to pull the boat into shape before you glue the midship side joints. Doing so should pull those seams together w/out having a gap.

The concave fillet (hard t) on the inside of a seam is more than a hole filler. Its job also is to spread the load where the two panels come together and to form the base for the fiberglass tape on the inside of the seam. The idea is to get a substantial amount of thickened epoxy on the inside of the joint - and look nice. Where you have the gap where the two panels meet, I'd put a piece of duct tape on the outside of the gap - bowed to the desired shape of the joint. Then cut a couple of pieces of plywood to fill the void. Don't have to be an exact fit, but will give the inside fillet a better base. Once the fillet has cured, remove the tape on the outside and fair the seam like everywhere else.

The purpose of the 1st coat of epoxy is to secure the tape to the wood, not completely fill the weave. Flaws are when the tape isn't wet out and you end up w/ white tape showing, maybe w/ an air void underneath. Too much epoxy is probably better than too little, but I didn't see any voids in you pictures.

Last question first. Use "chip" brushes, a natural bristle disposable brush available lots of places. Cheapest is someplace like Harbor Freight, if you have one nearby. Actually, these brushes are reusable, if soaked/cleaned in some solvent like vinegar, alchohol, etc. - NOT WATER! Water won't do a thing to the epoxy except make it gummier. Use a small block of plywood on each side of the end of the joint. Overdrill the outside block so the screw threads don't hang up in it. Don't know what the sponge would do. Premoistening the wood might relieve some of the initial stress, but it will dry out long before the blocks come off. They stay until the joints are glassed to take the stress. Hopefully you're using a slow curing epoxy. Don't need to be in a rush doing this stuff.

A slight bird walk - has anyone actually seen/used the "new Stanley Sweetheart" planes, other than in magazine ads?