| 
       From the Boatshop 
      by Ron Magen  
      quohog@worldnet.att.net   
      BUILDING METHODS; PRO & CON and 
      HOW & WHEN 
      or 
      Lessons Learned 
      "DECOY" {Wittholtz design}, along with "10-1/2 ft 
      Pointy Skiff" and "12 ft Fisherman’s Skiff" {Bolger designs} bring up an 
      interesting point; which "style" of construction would be most 
      ‘appropriate’ for which season {where weather and 
      temperature are a factor; i.e. unheated garages}. 
      Cutting of the individual parts is immaterial. That 
      depends on the size of the part - if I do the cutting inside or outside. 
      If outside, or in the garage, it depends on my physical feeling for heat 
      or cold. 
      Wholly traditional methods rely heavily 
      on fastenings; the adhesives are an adjunct. 
      If it takes a while for them to ‘set-up’ so be it; the parts are already 
      held in place. The only rate limiting temperature is that they don’t 
      freeze or crystallize. 
      
      Theoretically they could utilize lighter 
                chines and frames, IF upon basic completion, the hulls 
                were taken off their molds, set upright and epoxy fillets applied 
                to chine and frame areas.[or the molds left in, but the hull 
                removed from the strongback; molds removed after the fillets have 
                set] This would allow COLD WEATHER construction as the 
                temperature sensitive fillets would be applied LAST. At that 
                point construction time WOULD NOT be dependent on adhesive set-up 
                time. 
      The drawback is the MOLDS, STRONGBACK, and CHINE 
      ‘LOGS’ 
      The "MODERN MATERIALS" method typically 
      uses lighter scantlings, no chine strips {sometimes called "logs"}, few
      or no permanent fastenings, epoxy / fiberglass 
      sheathed. Because it uses epoxy fillets to hold it’s shape, it really 
      can’t be moved until the hull is finished. 
      Building time is therefore temperature dependent. For timely construction, 
      and good looking non-starved joints, the epoxy must set-up in a reasonable 
      time. The fillet mixture shouldn’t sag or ‘drain away’ before it reaches 
      the ‘gel stage’. For vertical surfaces the minimum is probably about 50 
      degrees F; 40 degrees F for flat, horizontal ones. 
      From the catalogs received, most of the 
      plans listed are based on ‘traditional’ techniques.{many are 
      apparently relatively old as well}. They may use ‘modern’ 
      materials like plywood or epoxy, but still rely on multiple frame and 
      chine log construction. Even some that specify "S-N-G" require building 
      assembly forms and molds. Of course, each seems to point to a specific 
      building frame for each boat design. HOWEVER, the
      " 2 X 10 " frame called out by John Gardner seems to be the 
      simplest. If I don’t intend to go over 12 feet overall, extending it to 
      " 2 X 12 " shouldn’t present a problem. Building a ‘Universal 
      Strongback’ from pressure treated 2 x 6 x 12's and 2 x 4 
      spreaders, bolted together, would be fairly cheap. { 
      and ‘collapsible’ for space saving storage } The drawback with 
      pressure treated is that it seems to "wet" and warps when it drys. RED 
      CEDAR is available for a little more money, but is lighter, dry, and seems 
      to ‘hold true’. The molds could be cut, in the solid, from 
      7/16 inch OSB or Waferboard and attached with 3/4 inch plywood ‘angles’ 
      and 2 x 4 ‘blocks’. 
      A ‘free plan’ included in one of the catalogs, uses 
      construction methods along traditional lines. "Frames" and a "Building 
      Ladder" are called out. Of course a set of "Stitch-N-Glue" plans are 
      available for $35.xx. Again, this points out the value of a ladder frame. 
      Also, NOT all plans have a "Stitch-N-Glue" version. HOWEVER, the 
      methods of the "S-N-G" technique can be combined with the traditional; 
      lighter scantlings can be used. 
      One of the seemingly ‘universal’ design points in 
      "S-N-G" is DEEP (Sticking far into the interior space from the hull 
      skin) FRAMES. This may be due to the pressures exerted by the sides 
      during assembly, or because there are only a FEW frames. By using square 
      sectioned frames and chine strips, along with clamps and gunnels, more 
      interior room could be achieved. 
      As a fairly general rule the hull material will be 1/4 
      inch ply. LAUAN; A-C; Marine Grade; your wallet - your choice. Battens 
      will vary between 1/4 inch LAUAN and ½ inch ply. If Bolger’s "NYMPH" is 
      any guide, the gunnels will tend toward 1 inch thick. This will give a 
      1-1/4 inch total thickness at the sheer. I would add an inwale 
      or inner clamp to increase this dimension. I like to have the outwale 
      replaceable and hold it in place with drywall screws. SILICON BRONZE 
      { Beautiful!} or MARINE STAINLESS is expensive. A good {1000 
      hour salt spray certified}, inexpensive alternate is McFEELY’s NO-CO-RODE 
      drywall screws, but the minimum length is 1-1/4 inches. 
      I’ve gone through the six most popular design catalogs 
      and where there is a gunnel at all this dimension seems to hold.. Jay 
      Benford’s book calls out a 1-1/2 inch half-round in one 11-1/2 ft. design 
      - simple, neat, and gives a 1-3/4 inch total thickness at the sheer. 
      The options seem to be ‘adjust’ the design or go to the 
      stainless screws. {bronze for clear finish or ‘customer special 
      order’ only} 1 inch, 1-1/4 inch, and 2 inch seem to be the most 
      useful sizes. The 2 inch is basically for skegs and keels. The Deep or 
      Course thread design seems to give greater holding power. 
      While GLEN-L Marine seems to have the cheapest price 
      for bronze screws, the shipping from CALIFORNIA is a killer!! JAMESTOWN 
      DISTRIBUTORS for an East Coast source of SILICON BRONZE screws and other 
      ‘hardware’. McFEELY’s seems to be the best source for "sheetrock 
      square drive" screws. CLARK CRAFT has WOOD FLOUR, so now I have 
      another source. RAKA MARINE for epoxy & cloth. MERTONS FIBERGLASS SUPPLY 
      for fillers & ‘stuff ‘. 
      
      SOME THOUGHTS on "FINISHES" and "PSEUDO-WOODS" 
      
      The "problems" with RUBENS NYMPH illustrate what a 
      learning experience is. And the VALUE of patience. 
      The Aniline dye, on the transoms, was perfect. Once 
      ‘aged’ it didn’t even ‘bleed’ when the epoxy was applied. However, a 
      couple of errors in subsequent procedures had me kicking myself; 
      FIRST ERROR - adding TO MUCH WHITE ‘filler’ for 
      second, or fill, epoxy coat. 
      SECOND ERROR - NOT WAITING for a ‘hard dry’ on 
      the varnish before painting the surrounding area with WHITE PAINT. 
      The epoxy makes a VERY HARD surface. The smoothness 
      depends on the prep work and timing. 
      The reason for using paint is to protect the surface it 
      covers; from ‘ageing’ and time / weather damage. Varnish, with UV filters, 
      does the same, but allows the surface to show through. 
      If the material is a "solid" wood, like the Mahogany of 
      the ‘classic’ runabout, then simply using multiple coats of finish is 
      enough. 
      Paint (OPAQUE paint as opposed to TRANSLUCENT colors), 
      is sort of self-explanatory. Everyone knows it by it’s nature, it’s long 
      history, the books & articles available, and the usually complete 
      instructions on every can. It’s maintenance is simple and logical, and the 
      indications of it’s need of repair or replacement are fairly obvious. 
      
      CLEAR finishes over stained wood require a bit more thought; 
                for both the builder and maintainer. In one of Dynamite Payson’s 
                books he says he did a "sacrilegious" thing. He felt 
                the looks of a certain boat would be improved by a Mahogany gunnel, 
                so he grabbed a can of stain and made one !! I don’t have any 
                problem with that !! { want to see the BURMA TEAK "sunning 
                roof" on our Malamute’s house ? } 
      The ‘problem’ is the future, a rapidly approaching one 
      in the case of an outwale on a working dinghy. I usually 
      make mine of a "consumable" wood, attached with screws, and a simple, 
      cheap ‘teak oil’, finish. Easily maintained or replaced. 
      However, I like a "classic" Red Mahogany color for my
      inwales, clamps, transoms, and
      thwarts. If someone wants to pay the price, or use the boat 
      as a show piece, then by all means use TRUE MAHOGANY. It may be a bit of a 
      search and WILL BE a $TIFF PRICE for 3/4, 4/4, 5/4, 
      etc. stock of practical width. 
      I need to have my boats SELL, and WANT to see them 
      USED. I also like the touch of the ‘classic’ or traditional. To put these 
      together well takes thought and compromise. 
      The ‘practical’ material of today is A-C plywood. On 
      either side of that is LAUAN, and imported Marine Grade plywoods - "you 
      pays your money and takes your choice". Bolger, Payson, Devlin, and 
      several others are who I point to for long experience. Typically the A-C’s 
      appearance is plain and uninteresting. It does have a grain surface look 
      as opposed to LAUAN which is rather bland and featureless. [Red Cedar 
      lumber is somewhat like LAUAN in surface appearance] To my 
      sensibilities a translucent coloring turns things completely 
      around. 
      MY PREFERENCE is for Red Mahogany, but I’ve used 
      WALNUT, SPECIAL WALNUT, BURMA TEAKWOOD, JACOBEAN, and other tones on 
      different projects. Indoors and out. The only caveat for color choice is 
      the logical; dark colors absorb heat. Heat, and sunlight, destroy 
      finishes. That’s one of the reasons for multiple coats of UV 
      sunscreen varnish. 
      The stain, or dye, changes the ‘character’ of the wood. 
      All well and good. Now the air, the sunlight, the heat, the humidity, etc. 
      can go to work and change what you have "created". 
      This missive started out with a reason for a finish - 
      to protect. If this boat, or other project, is yours and will be for all 
      time, make a note of the Brand and Color of the stain, then apply a couple 
      of coats of varnish or indoor clear finish, and your done. WHEN future 
      repairs become necessary, and you sand through the stained surface, you’ll 
      know how to ‘repair’ it. Simple enough. 
      If this is going out of your reach a little thinking is 
      required. 
      If you have gotten this far you have already decided a 
      bit of maintenance WILL BE REQUIRED. Otherwise you would have 
      painted over everything. Tell the ‘buyer’ the info on the stain and it’s 
      his worry. Maybe O.K. if you’ve used a standard stain right out of the 
      can. BUT what if you have ‘customized’ one, or don’t want to 
      intimidate the buyer? 
      Back to protection. I’ve used Aniline Dye 
      (alcohol soluble2) for a couple of reasons. Wood penetration 
      without swelling the pores, raising the grain, quick drying, and tone / 
      color control. I didn’t want to close the pores because I want the best 
      epoxy ‘grip’0. NOTE: LET THE DYED WOOD "AGE" for several days. 
      Apply one or two coats of unthickened epoxy to the dyed 
      wood. You’ll notice how the first coat is absorbed into the wood; open 
      pores. You should now have a fairly hard, fairly abrasion resistant 
      COLORED surface. Add a third epoxy coat if you desire, or the wood seems 
      highly absorbent. The idea, up to this point, is abrasion (sanding) 
      resistance for future maintenance. If it’s warm, and your 
      using a FAST epoxy, you could get on 3-4 coats in a day. Unlike varnish, 
      you do "hot coat" epoxy. 
      At this point you have a filled, ‘harder than wood’ 
      surface. If you have the patience to let the epoxy ‘cure’ for about a 
      week, you’ll have a HARD surface. If you see ‘whiskers & 
      specks’ on the surface, once the epoxy has set beyond the ‘gum-up 
      sandpaper’ stage, give it a water & drop of detergent wipe down. This will 
      remove any possible amine blush residue. Then give it a light 
      sanding, or rub out. Depending on your technique, the surface may look 
      like it has 5-10 coats of varnish. It may have the LOOK and
      DEPTH but NOT the UV RESISTANCE. 
      It is harder than varnish but sunlight will degrade it. 
      Simply treat it as the "next to last" coat of a 
      terrific varnish job. At minimum, --- give it a 220 
      grit ‘scuff sand’ and a coat of good, hard UV 
      varnish. Then, when THAT coat has dried for 24 hours, 
      give it a 320 grit ‘scuff sand’ and a final coat of varnish. 
      
      Some Thoughts About GAP FILLING 
      One of the problems with the Nymph prototype was large gaps at the 
      chines. Part of this could be resolved by STITCHING specific 
      problem areas. I didn’t do this and had filleting mixture forced 
      through by my pressure, even though I had masked/taped the 
      outside seams. The use of a course, glass fiber added 
      mixture increased the problem. ‘Painting’ the area with unthickened epoxy, 
      then insetting a gauze or OPEN WEAVE drywall tape and allowing it to 
      set-up before filleting should correct this. The ‘trick’ is PATIENCE. And 
      adding at least 2 layers of external fillet. An under layer 
      of course, fibrous material into the seam and undercut; let it 
      reach gel state, then put on an outer or smooth surface layer.   |