Pitfalls and Learnings

[Martin Wallace]

Hi All,

I am about to order plans for a Tiki 26 which I hope to start building in the next few months. I am wondering if there is anything I need to look out for when getting started or any building equipment that is "invaluable". I'm hoping to learn from others mistakes as much as I can.

 

Looking forward to your replies.

 

Cheers, Marty.

[paul anderson]

If you haven't got a level workbench long enough,make one that can take the length of the hull for the stitching the keel.I used cheap chinese tables for this,worked a treat. Measure twice cut once.Use slings for the hulls.Get as much of the consumables as you can so you are not running of to the shops all the time.Buy a heap of mixing cups/containers.Learn to smooth your fillets means less sanding.Clean all dropped epoxy.wear gloves.Buy tongue depressors from pharamacy for mixing.

good luck.

[Penn D]

Read, read, read.... asks questions, ask questions ask question, but above all work, work, work!!! Meditate, eat, think..then work some more.
Epoxy is very forgiving.. you wont really need any "special tools"... get your plans and start cuttin bro:)

[Omar M. Rashash]

Building sequence/Shop process

The typical wood boat is built by making the hull and then attaching the rest of the boat to it. Before I went to school to learn how to build wood boats, I got an undergraduate degree in Industrial Management, so my approach is a little bit different. You’re going to build two hulls and then, either have to move them someplace else, or have to work around them in your shop. Rather than do that, I’d suggest building the hulls last. Do everything you possibly can on the boat before you start assembling the hulls. Cut and mill all the materials for the boat, “kit” up as much of the project as you can, build the rudders, build the crossbeams, and build the mast, you get the idea. You’ll gain experience and confidence with your tools and materials. Additionally, the items you produce are a lot easier to move than built hulls, and take up much less storage space.

Milling materials

Cut everything you’re going to need for this project before you start cluttering up your shop. If you need 200 lineal feet of ¾” by 1-1/2” Douglas Fir, then saw/plane all of it with single machine settings. This will save you the time to readjust machinery to duplicate parts later. Kit the boat, cut everything you can that doesn’t need to be fitted to another part. Once you start construction, your primary task should be assembly, with some parts being cut to final size.

Cutting out parts

Since you’re building a catamaran, that means almost everything you’re going to make has ether a twin or lots of siblings. Cut in sets, rather than laying out the same bulkhead on two pieces of plywood, and cutting them out. Stack the materials, do a single layout, verify that layout, and cut and trim to size the stack as a single piece. This will help keep your hulls symmetrical, even if they are assembled one at a time. If you need six of something, and the machine setup time is longer than you’d care to repeat, make some extra parts. Murphy has a “thing“ for boat builders. Some parts can’t be trimmed to size ahead of time because they must be fit to the hull(s).

Mixing epoxy

Yes, measuring epoxy by hand is an effective technique, but not one I’d like to repeat on any boat 30 feet or larger. My preference would be to go with this setup from Michael Engineering http://www.michaelengineering.com/Pumps/Manual/StickyStuffDispenser/. This is the same machine sold by West at a much better price, and in whatever ratio you desire. If you properly maintain it during the build, you should have no problem recovering most of your investment by selling it.

Masking for epoxy

A little bit of planning will tell you what areas should not have epoxy initially applied during construction. By utilizing cheap tan masking tape, and removing it before the epoxy cures, you can avoid having to sand areas to create tooth for the next application of epoxy.

Filling holes under glass

The normal process is to fill holes with epoxy, wait for it to cure, cut and then sand the surface smooth, before the application of cloth. This can be very time consuming, labor intensive, and unnecessary. If you apply a thickened epoxy mixture into the holes, just before the cloth is applied, the cloth will self -level the hole. Remember, any filler applied under the cloth covering, must be harder than the cloth. This means while cotton fibers or colloidal silica may be used to thicken the epoxy, micro balloons and other lightweight fillers aren’t permitted.

Some closing thoughts:

Epoxy is much easier to remove while it is wet, and much easier to cut when it’s a day old rather than a week old. If you tend to wait too long, a wood rasp is the ideal tool to reshape cured epoxy, rather than 36 grit.

Power tools may be your friend, but it’s been my experience that power tools simply enable you to screw things up faster. Properly used (as in sharp) hand tools can be faster, safer, and much easier on your hearing.

Learn how to sharpen and use a hand scraper. It will save you a large volume of sandpaper and reduce the amount of dust you end up breathing.

The extra ten minutes you spend figuring out how to do something safely is much more productive than the five hour visit to the Emergency Room and the two-four weeks you can’t work on the boat.

Some of these things were learned through experience, which is usually learning how to not do things in the future.

Omar

[Marty Peters]

Start collecting margarine and ice-cream containers as they make great mixing bowls for epoxy. Don't worry about cleaning them just leave overnight and the cured epoxy comes right off if you bend and squeeze them. Get a good 3M facemask with particle filters for sanding  and good vapour filters for painting. Get a good digital food scale for measuring / weighing epoxy and wrap it in clingfilm / saran wrap and it will last way longer because you will spill epoxy on it. Remember, epoxy doesn't stick to shiny things..

When laying fibreglass mat let it go tacky then apply fairing compound (epoxy, silica and microballoons) before it sets and you save lots of sanding. I made a post somewhere about fairing. do a search on the forum and i'm sure you'll find it. A great epoxy primer is Jotun Penguard HB (High Build), it will fill minor imperfections and is easy to apply and sand. I cant speak highly enough about this paint..

Good luck

Marty

[curt goodnight]

good topic-    this website is one of the most important tools i have found. [sure wish it had been around when i was into the meaty parts of my build years ago]   Other thoughts:  vinegar and denatured alcohol instead of acetone for brush/tool clean up.   Become handy with drywall knives instead of sqeegies.  In addition to the standard power tools [sanders, skil saw, impact driver , drill etc] I recently added a multi tool - it accepts a variety of cutting blades and a small trim sander pad- i was skeptical at first but it has sure been useful.   shop aprons similar to those worn in meatcutting shops offer decent protection and are cheap enough to toss after they too become waterproof and stiff.... likewise    I regularly stock up on cotton sweat pants and long sleeve tees from our local second hand  store- 

[Martin Wallace]

Hi Guys,

Thanks for your input, sounds like I need a multitool and clamps, clamps and more clamps!! I'm really looking forward to getting strarted, hoping to launch next NZ summer, around December 2016.

No doubt I'll have plenty of questions during the build so glad I have access to so much experience.

Cheers,

[Éric Bouvéron]

Bonjour,
Omar M. Rashash said:
«Cutting out parts:
Cut in sets, rather than laying out the same bulkhead on two pieces of plywood, and cutting them out. Stack the matériels, do a single layout, verify that layout, and cut and trim to size the stack as a single piece. »
Sounds great, but on the Wharram instructions, it is said to cut pieces one by one, since a jigsaw blade will twist and not provide an accurate cut on the lower sheets. So, what is used to make the cut? Are the sheets nailed together to make a solid block,and the nails removed after the cut?

On the same post, I like the idea about building everything but the hull first, actually I was thinking of it.
Like the pump as well, but hopeless to find one here.
Éric

[Ian Bamsey]

I can second the comment re Jotun HB. That paint is fabulous.

Marty Peters said:

Start collecting margarine and ice-cream containers as they make great mixing bowls for epoxy. Don't worry about cleaning them just leave overnight and the cured epoxy comes right off if you bend and squeeze them. Get a good 3M facemask with particle filters for sanding  and good vapour filters for painting. Get a good digital food scale for measuring / weighing epoxy and wrap it in clingfilm / saran wrap and it will last way longer because you will spill epoxy on it. Remember, epoxy doesn't stick to shiny things..

When laying fibreglass mat let it go tacky then apply fairing compound (epoxy, silica and microballoons) before it sets and you save lots of sanding. I made a post somewhere about fairing. do a search on the forum and i'm sure you'll find it. A great epoxy primer is Jotun Penguard HB (High Build), it will fill minor imperfections and is easy to apply and sand. I cant speak highly enough about this paint..

Good luck

Marty

[Blanc Jean-Paul]

Hello any body
sorry but in french.
La méthode de découpe de plusieurs feuilles de cp avec une scie sauteuse ne marche pas. Pourtant j'ai tout de même utilisé cette méthode. Sauf que j'ai utilisé une défonceuse avec une mèche à copier. Méthode : découper les p anneaux ensemble avec une marge, faire la finition sur le panneau tracé, ( c'est à dire ajuster aux côtes),rempiler puis avec la fraise à copier, faire lrs autres pièces. Dimensions garanties.
Voilà voilà comment j'ai pu faire quatre pièces identiques.

[Omar M. Rashash]

The easiest way to gang sheets for cutting is to use screws and washers, nails or staples require too much work to remove. My preferred method for cutting materials is a Skilsaw set to a shallow cut for sweeping curves. This works well to about 3/4" (18mm) material thickness. Sharper curves or thicker than this, which would be about 1-1/2" (35mm), or two sheets of 3/4" plywood, I'd use a jigsaw with a sharp blade and cut a little oversize, if that's what's needed to be able to trim down to 90 degrees. You should not be trying to cut exactly to a line, you should cut oversize, and then trim to the line by hand.

It's also possible to use template router techniques, where one part is used as a template to make a second, but that is an advanced technique.

Omar
 

Éric Bouvéron said:

Bonjour,
Omar M. Rashash said:
«Cutting out parts:
Cut in sets, rather than laying out the same bulkhead on two pieces of plywood, and cutting them out. Stack the matériels, do a single layout, verify that layout, and cut and trim to size the stack as a single piece. »
Sounds great, but on the Wharram instructions, it is said to cut pieces one by one, since a jigsaw blade will twist and not provide an accurate cut on the lower sheets. So, what is used to make the cut? Are the sheets nailed together to make a solid block,and the nails removed after the cut?

On the same post, I like the idea about building everything but the hull first, actually I was thinking of it.
Like the pump as well, but hopeless to find one here.
Éric

[Omar M. Rashash]

BTW, that's 4 hull sides being cut at once for a Hitia 17, a total of about 16mm.

[Ricardo Aráoz]

Problem with templating is that the smaller router bits for templating are 1/2' bits, and that's too much material elliminated, I'd rather use the jigsaw.