Chebacco News

Number 2, February 1995

Since Peter Spectre published details of the newsletter in WoodenBoat, the readership of this newsletter has almost doubled. Interestingly, practically all of the readers are builders of Chebacco – the only account I’ve had of her sailing performance was from Phil Bolger himself, of which more later.

So far, none of the readers (except for Brad Story) has completed construction of a Chebacco, and about half are still at the planning stage and haven’t applied saw to wood yet. This is a pity, because lots of us would like to hear about cruises that Chebacco owners have undertaken – these would be wonderful inspirational fodder to keep us going through the construction process.

A number of readers were disappointed in the quality of the photos in the last issue, so I’ve had them scanned into a computer and printed out in dot style, which photocopies much better.

I’d like to thank those readers who have sent me a donation to help cover printing and postage costs. For information; the (low volume) photocopying and postage involved in producing this newsletter costs me about $2 each.

Please keep your letters coming – even if they are only questions. Discussions of questions are likely to be of interest to more than one reader.

Bill Samson,
88 Grove Road,
West Ferry,
Dundee,
DD5 1LB,
Scotland.

The Question of Ballast

I’ve had a couple of queries from readers about whether Chebacco should be ballasted. Phil Bolger says:

“The Chebacco was meant to sail without any ballast. We have, and you can, experiment with the effects of ballast simply by noting the effect of various crew weight and placement. They are very good in rough water and forgiving in squalls and with prudent and skilled handling and not exceptionally bad luck would get over the North Sea, or the ocean for that matter; but by present day standards they are inshore and fair-weather boats.”

Brad Story told me, last year, that he didn’t see any need for ballast on the Chebacco, although he knew of one owner who had put in a couple of hundred pounds of it.

My own experiments with an eighth scale model of Chebacco (sheet ply version) indicate that she’ll self right from a ninety degree knock-down, but if she goes much further than that she’ll go all the way over. On the other hand, a capsized Chebacco floats very high and certainly won’t sink as many ballasted boats would. This is all academic, though, because there have been no reports of a Chebacco ever having capsized.

Sailing Chebacco

Phil Bolger writes:
“We had a good sail last week in a borrowed Chebacco 20; the last of the season as we’re starting to see ice. This one carries a stronger weather helm than I would prefer. It may be a quirk of her sail cut, or something, as there have not been any complaints about it, but if you have not yet completed the mast step and partners there would be no harm in allowing each of them to go three or four inches further forward. Another possibility is that we had her centerboard too far down, as there was no marking on the C.B. pendant to show where the board was.”

Building Sequence for a Sheet Ply Chebacco

Unlike many other of Phil Bolger’s tack and tape designs, there is no published building sequence for a Chebacco. One reader wrote that he’d be wary of starting on a Chebacco without something akin to Dynamite Payson’s “Build the Instant Catboat” book to guide him through the process. I hope this numbered sequence of steps, which are based on my own journal of construction, will help in some measure to fill that gap.

1. Buy plans – these are available from Dynamite Payson.
2. Get hold of Dynamite’s book “Build the New Instant Boats” which describes lots of useful techniques which are applicable to Chebacco.
3. I’d strongly recommend building an eighth scale model, using 1/16 inch ply. This will help to sort out any uncertainties you may have when reading the plans, without costing an arm and a leg if you make a mistake.
4. Get your plywood. I used 22 sheets of half inch ply. If you intend to laminate the for’ard end of the bilge panels, rather than twist the half inch ply, then make that 20 sheets of half inch and four of quarter inch. There’s something to be said, too, for laminating the cabin roof. If you do that you’ll need 18 sheets of half inch and 8 of quarter inch.
5. Choose your building site. It is undoubtedly best to build in a shed if one is available. I, and a couple of other guys have used a temporary polyethylene tunnel like the one whose plans can be had from Stimson Marine – although it might get a bit hot in warm climates. If the climate is warm, then you can build out of doors and throw a tarp over the boat when you aren’t working on it. You’ll need at least 3 or 4 feet all around the hull for comfort when you are working on it.
6. Set up your backbone. The style of backbone is up to you. I used a “ladder” made of two by sixes, with the “rungs” spaced to match the bulkheads/molds. I set this up on legs about a foot off the ground with packing under the feet to keep everything level – this is crucially important if you want to avoid building a twisted hull. Gil Fitzhugh of New Jersey is using a plywood box section backbone which is working very well.
7. Mark out the bulkheads and transom on the sheets of ply, following the dimensions given in the plans. It isn’t necessary to loft the lines as the dimensions on the plans are accurate enough. Marking out actually takes longer than cutting them out! I found that this was very hard on the knees and would recommend getting knee pads before you start. Incidentally, it’s a good idea to plan the layout of components on the ply sheets before you start, in order to minimise wastage.
8. Cut out the bulkheads and transom. The molds (2 and 3) can be made from what we in the UK call “chipboard” – could this be the same as US particle board? Most of the cutting out can be done with a hand held circular saw – the curves are pretty gentle. A sabre saw (UK “jigsaw”) can also be used but gives wobbly edges that need planing up. I used (masochist that I am) a hand saw – crosscut with hardened teeth – which got through the wood surprisingly quickly and without the nervous tension that always seems to go with handling power tools. Try it!
9. (Optional) You can pre-coat all your plywood components with epoxy after cutting them out. It’s much easier to get a drip-free coat on a horizontal surface than a vertical one. The downside is that all the gluing surfaces need to be roughened up and you’ll need to protect the epoxy from UV degradation until you paint it. It’s also a pain having to wait for this to dry before you get to the next stage.
10. Make the stem. I laminated mine from offcuts of half-inch ply (seven layers) glued side by side and liberally coated with epoxy. I cut the bevels on a bandsaw, making sure not to cut too deep. The final bevels will be determined once the stem is set up with the bulkheads and molds.
11. Before you set up the bulkheads it’s a good idea to glue on the one and a half by four “floors” on bulkheads 4 and 5 and the framing around the transom. I used a mixture of yellow (“pitch”) pine and construction grade fir for these. The plans give accurate instructions for bevelling the transom and its framing – do this now.
12. Following the measurements given in the lines plan, fix the bulkheads, molds , transom and stem to the backbone using simple battens and nails which will be removed later. Be very careful to line everything up accurately using a spirit level and double check the heights of the gluing surfaces for the bottom. I found a lot of fiddling was necessary at this stage. Once you’ve fixed on the topsides you are committed and there’s no going back!
13. Mark out the topsides and bottom on the ply, using a bendy batten to mark fair curves for their edges. This is vitally important for the finished look of the craft. Cut them out and join up the parts with butt straps as shown in the plans. Precoat with epoxy if desired, then roughen up the gluing surfaces.
14. Mark the positions of stem, molds, bulkheads and transom on the topsides and bottom.
15. Temporarily fit topsides to bulkheads using screws and cleats as necessary. An extra pair of hands helps here though it can be done singlehanded by suspending the topsides with string from the shed roof. Some fine adjustments to the bulkheads will probably be needed at this stage.
16. Once you are satisfied with the positioning of the topsides, glue them on and apply epoxy fillets. Notice that there is no need to bevel the bulkhead edges. The epoxy fills the gaps and, indeed, a stronger joint results.
17. Fit the bottom and glue it in much the same way as the topsides.
18. The next thing to do is make the bilge panels. No dimensions are given for these on the plans because the fine adjustments of the previous stages could result in significant variation in the bilge panel shapes. The panels are made a section at a time and then fitted, with butt straps being applied on the boat.
19. The shape of the bilge panel can be determined by laying a long sheet of wrapping paper (as stiff as possible) along the gap between topsides and bottom that the bilge panel will fill. The shape of this gap is transferred to the paper by rubbing coloured chalk along the edges. It is best to do this on each side of the boat separately, as there could be small differences. Notice that because the bottom and topsides are not bevelled, the shape traced will be too large by about a half inch. This can be trimmed away later as fitting of each panel progresses.
20. Mark out the shape of the front section of the bilge panel on a sheet of ply and cut it out. Fit this section starting at the stem and screwing on cleats inside to make it lay against the topsides and bottom, working aft, trimming it to size as you go. There is tremendous twist in this panel and I used a Spanish windlass (twisted rope) attached to a clamp at the aft end of the panel to pull it into position. There is a colossal amount of potential energy in this twisted panel so take care that it doesn’t accidentally come loose and decapitate you! I found that, with the plywood I was using, if I left it clamped in position for a day or so, the plywood took up its shape and had less tendency to spring back when further work was done. [Alternatively, laminate this section in situ using two layers of quarter inch ply.]
21. Glue front section of bilge panel into position, both sides, and apply epoxy fillets as necessary.
22. Fix butt straps to front sections of bilge panels. (This may involve trimming one of the molds.)
23. Fit and glue the other two sections of the bilge panels. They are easy peasy compared to the front section.
24. Tape all the joints, inside and out, with 4 inch glass tape. (I won’t go into details here – Dynamite explains it beautifully in “Build the New Instant Boats”.)
25. Fair the outside of the hull using a power sander ( – I like the dual action type – ) and a long sanding board with 60-grade paper on it. Fill all hollows and sand out all humps at this stage. It sounds straightforward but takes ages to do right. Any unfairness at this stage will stick out like a sore thumb on a glossy hull. BE SURE TO USE A BREATHING MASK AND GOGGLES WHEN YOU DO THIS – EPOXY DUST CAN BE VERY BAD FOR YOU!
26. You can now glass the outside of the hull, or wait until the centerboard case and keel are fitted before you do so. I did it at this stage because it is less fiddly.
27. Apply a layer of six ounce glass cloth (I used plain weave) to the outside of the hull, using about three coats of epoxy to fill the weave. Beware of drips, sags and runs! Dynamite’s book again explains the process very well.
28. This is a good time to make the centerboard case (and the centerboard). This is a straightforward bit of joinery and needs no special explanation. NOTE, however, that the case protrudes through the bottom of the boat to the level of the outside of the keel.
29. Fit the centerboard case to the hull. This is an awful job as it involves cutting the slot in the bottom and making sure it lines up accurately with the slot in bulkhead 4 and its associated floor. I used a combination of sabre saw, handsaw, abrasive disk and files along with a liberal sprinkling of four letter words as I was working inside the hull and sawdust, epoxy dust and glass dust rained down on me. Goggles are a good idea – I didn’t wear any and had to go to hospital to get a sliver of epoxy removed from my cornea at this stage!
29. The keel pieces, cheeks and outer stem can now be made and fitted. I stuck to the plans with built-up hollow keel (remembering the drainage holes). Brad Story and other builders have gone for solid wooden keel pieces – fir or oak. With my small scale woodworking equipment the built-up option was easier. I made the stem from two thicknesses of one and a quarter inch thick fir.
30. Glass the stem and keel.
31. Back to sanding and fairing. This shouldn’t be too bad if the last lot was done well. Again take precautions against inhaling the dust.
32. Once the hull has been sanded and faired it is a good idea to paint it so that there will be no worries about UV degradation of the epoxy. I used a white epoxy paint undercoat (Veneziani “Plastolite”) which was sanded, and fairing done where the paint (inevitably) showed up irregularities which had been hiding until now. I used a Veneziani polyester filler (rather like car body filler) which applied easily and sanded well. This was topped with a 2-part linear polyurethane gloss (Veneziani “Gel Gloss”) applied using a paint pad. The finish is unbelievably hard. I used the same stuff on a skiff five years ago and it hasn’t needed repainting, so I claim the extra expense of these fancy paints is worthwhile. Having said that, most builders use conventional marine enamel on top of the epoxy. So it’s up to you. The waterline needs to be struck at this stage. (You figure out a good way; I can’t.) The area under the waterline should be painted with antifouling. I put this straight on the epoxy. It could be better to paint the epoxy first with conventional paint and then antifouling paint – I don’t really know what is best. I used a long handled roller to apply the paint to the inside to the centreboard case.
33. Turn the hull over.
34. Fillet inside joints and glass tape them.
[Lapstrake builders are on their own up to this point – from here on in it’s the same process]
35. Add remaining floors.
36. Fit and glue inwhales.
37. Fit and glue framing for seats, carlines for decks.
38. Finish inside of hull with 3 coats of epoxy. Foam roller application is easiest. Watch out for runs!
39. Make decks, seats, outboard well panels etc. to fit framing – precoat with epoxy and then glue/nail in place.
40 . Make cabin sides and glue into position.
41. Add framing to tops of cabin sides and fair in preparation for cabin roof.
42. Cut out cabin roof and glue/screw in position.
43. Make hatch slides (I used fir) and glue/screw in position.
44. Add trim pieces to hatch opening and mast opening.
45. Make slides for washboard and fix.
46. Make hatch and washboard.
47. Cut ventilator holes in rear compartments and fix on clamshell covers.
48. Fix on “shelves” to support floorboards in cockpit.
49. Make and fix mast step.
50. Make floorboards – loose fit.
51. Glass decks and fair surface.
52. Paint.
53. Make spars; get (or make) sails.
54. Add fittings, cleats etc.
55. Rig her up and go sailing!