Told you I'd have questions

[wagonmaker]

Ok guys here goes.......my skip jack plans call for ac exterior ply. is the stuff I have been using forever from the box stores what I want, or something else?.....It also specifies waterproof glue, tight bond 2 or 3 ok, suppose to be weatherproof & waterproof respectively, or maybe the polyurethane gorilla stuff ?, what do I need to use?..........lastly, the screws, does it matter that much? I know the bronze are maybe overkill. I was thinking maybe the deck mate type, have used them with great success on decks & remodeling jobs, or can I use a really cheap screw such as a drywall screw & remove them before filling? Thanks , I'll stop at this for now, don't wanna wear out my welcome.....W

[Charlie Jones]

San Antonio eh? Ever get down to Port Lavaca? If you do give me a yell and come by the boat shop- we can talk for hours about building boats around here

[Barry Pyeatt]

OK, here is the deal on ACX plywood.

When the plans were published, many moons ago, Doug Fir ACX was a really good plywood and totally suitable for this type of use. Doug Fir marine better choice due to lack of voids, higher quality control and edge glued plugs. Face veneers were also thicker.

Now Doug Fir Marine would be a minimum for quality in my mind if you want the project to last a long time and not have any issues with voids and thin face veneers. Also on the 3/8" it is five laminations rather than a thick center core and thin face veneers. The more laminations the more even the stresses are within the plywood sheet.

Many are choosing to use Exterior graded Meranti, Aquatek or MDO. MDO is the plywood that they use for highway signs that have to withstand the weather for long periods. It has a resin saturated paper coating which makes finishing a snap. Also means you could in theory go without glassing to prevent the plywood from checking. I would still glass the exterior though.

Nothing wrong with the Weldwood/Dap Plastic Resin glue. It comes in powder form which means you mix it with water. It has a good working time and is waterproof unless you plan on using the boat in boiling water.

Many use epoxy but it has only one real drawback other than working time. You can't clamp down on it really tight because it needs to avoid being squeezed out in order to have a good solid bond.

Only challenge with the polyurethanes is the foaming as it begins to cure. If you don't mind scraping that off it works great. Much wider temperature range for use than either of the others.

Stainless steel screws are not all that expensive and will work well. If you have an ACE Hardware near you they carry them at reasonable prices. Other wise galvanized will hold up for a long time without issues. Not zinc coated but galvanized.

I would leave most of the screws inplace rather than removing them. Helps to have a good mechanical fastener along with the glue.

Don't be afraid to ask questions, the only stupid ones are the ones that don't get asked until it is too late to do something about it. :roll:

Lots of good information and experience represented on this forum and willing contributions. There is always more than one way to build these boats and they have been built dirt cheap and with very high quality materials too. From rough work boat finishes to sleak high quality yacht finishes. Choices are yours to make. Have fun! And get down to visit Charlie if you can arrange it.

[Charlie Jones]

Gonna be starting a new boat soon too- more later

[Frank Hagan]

Barry has it pretty straight. You can save some money on a Skipjack by using exterior ply (ACX grade here in the US), but you usually have to pick through the pile to find anything good. Most of it is really questionable.

Sometimes you can find luan underlayment plywood that will work well too, but I've only seen it in 1/4" here in my Home Depot. It has a better face than fir or pine plywood.

How many sheets of plywood do you need to buy for the Skipjack?

[wagonmaker]

Thanks again Barry, Charlie & Frank...........I appreciate the info Barry, makes sense to me. This is my first boat building project, except for a 12 ft catamaran I started in high school about 30 yrs ago. I remember lofting the ply & stiching up the seams & using the water mixed glue. I never got the boat finished, my mom threw me & it out of the garage after a few months to get her car back inside...........Frank , the materials list says 2 sheets of 3/8 & 4 sheets of 1/4 ply, so wouldn't be that expensive regardless of a higher quality I suppose.

Charlie I do appreciate the offer & would love to visit you on the coast. It just might excite the wife a little, although she is coming around to sailing..... thanks again guys, Wayne

[Frank Hagan]

Well, with 2 sheets of 3/8" and 4 sheets of 1/4" ply you could run up a pretty "large" bill with really good marine plywood. The Skipjack is a pretty small daysailer, and you are faced with the first of what will become many hard decisions.

I thought I would keep my Weekender about 5 years, and then move up to a bigger boat if I liked sailing. So for me, going with inexpensive materials that wouldn't cramp the family budget was important. My boat didn't end up near the level of what the pros around here build ... I think Charlie built one of the best-built Weekenders ever. But I enjoyed my boat, and it served its purpose. I never really had a regret about using lumberyard materials and recycled wood from other projects, but I think if I were to build another boat, I would go with reasonably good materials like Okume plywood. I think it goes for about $75 - $85 a sheet for the 3/8" and $65 - $75 a sheet for 1/4" (many of the guys here have bought recently so they can tell you what it is now).

Assuming an average of $75 a sheet, that's still $450. You could save money by not using fiberglass cloth and just sealing the Okume with epoxy. That's really not a good option with lumberyard fir or pine plywood, as it needs the fiberglass cloth to keep the surface from developing cracks called "checking". You would save about $100 to $150 that way. That narrows the gap between cheaper plywood and marine Okume plywood.

But you'll have to decide which way to go. There's a strong argument in favor of using better materials for the hull of the boat, because that's not something you can upgrade later. This argument says that you can skimp on sails, because they are easy to replace. You can skimp on rigging, because that's easy to replace.

But to replace the plywood on the hull, you have to build another boat!

Wait, did I say that was a reason to use the good stuff, or the bad stuff?

[Barry Pyeatt]

Worth doing a little shopping around. There are so many decisions to make in building a boat and the quality of the materials is subject to a lot of discussions and goes all over the place. I'm a lot like Frank in using reclaimed and recycled materials were ever possible. I look for old growth Doug fir as an example with its tight grain and high ring counts. Not possible to get anything like it anymore without spending a small fortune but quite often really good shelving is being set aside and it can be a great find. Same with material to fabricate spars. Might not look so great on the outside but good wood is still good wood.

If I were going to build a Skipjack for my own use I would do as Frank is suggesting, Okume plywood, especially with 3/8 and 1/4 thicknesses. The plywood such a relatively small portion of the total outlay when you compare just Ok plywood with good quality marine ply. And it is such a joy to work with by comparison. Easy to upgrade other things later on as Frank suggests. But the plywood is the hull. And good stuff will last longer and finish out easier.

Just my 2 cents worth too. :wink:

[Andrew_Butchart]

The Skipjack looks like a fun little boat. You may want to also check out Ed Jones' skipjack that he built and later sold at http://www.geocities.com/edskipjack/SKIPJACK-PAGE-1.html

Rather than the designed lateen rig - which is an easy to use and learn setup, he went with a gaff rig like on the Weekenders. It looked really sharp and I believe sailed pretty well too.

I also believe that another skipjack recently launched by a member here had put on a small cuddy cabin into it.

[umop_apisdn]

If you decide to go with the box-store plywood, definitely use SS screws, and leave them in. Otherwise you are trusting the glue layers inside your ACX plywood to hold your boat together - something I would not do! :shock:

If you go with high grade marine plywood, then this is probably not an issue.

Noel

[Charlie Jones]

What's the sail area on the skipjack? Cause I have a spare lateen rig off a Dolphin Sr. 85 sq feet though.

[Brian Walters]

I gave up looking at lumberyards and box stores I just plain couldent find any marine plywood anywhere, So I went to this place online and ordered what I needed and the shiping was unbeleveably cheap! You may want to look into it. Heres the link...

http://alliedveneer.com/boat-building-plans-marine-plywood-information.html

Brian.

[Ken_StJohn]

I second that, Ray. There's a few of us who have learned the hard way about the heat of the catalytic reaction too!

With regard to the Resin Glue, I have followed through with DAP engineering and complained to corporate folks at A-- hardware stores who were unaware of the local issues. Within a week and a half they were nice enough to correct the situation at the warehouse and had fresh stock put into my local store. I mentioned how a lot of folks were using this stuff to build boats and the obvious connection to human safety. They were also nice enough to ship me two cases of 1-lb tubs free. Can't beat that customer service!

[Barnacle Jim]

Howdy and Ahoy Wagonmaker,

You'll find a lot of good and helpful advice here on this board. I am no boatbuilding expert, but I can tell you what has worked for us. Our boat is not yet finished, but the wood has been exposed to the intense Arizona elements for some 3 plus years. So, for what it's worth, here is a summary of what we did, along with some photos

[Charlie Jones]

What problems did you have with RAKA as an adhesive? Works just fine for me, and has for several boats now, and I work in high temps also. Curious about your difficulties.

Epoxy won't harm foams. You can glue styrofoam, Urethane, etc quite well using epoxy. DON'T try using polyester with the styrofoams though- you'll wind up with a melted mess- the styrenes in polyester will turn styrofoam into a liquid.

Nice looking job- what's the design? Vaguely reminiscent of a Sam Rabl boat.

[capt jake]

We used RAKA for most of our boat. I suspect that the RAKA epoxy is already thinned and therefore goes a long way in application. Thinned epoxy also helps should you decide to fill the wood cells on the interior of your boat. We did this and painted the surface for good measure as well. However, should you add thickners or try to use RAKA as a glue, you may have problems.

Well, I have to disagree with that. Raka is not a 'thinned' epoxy. It's formulation makes it a thinner viscocity than some others, but it is not 'thinned' like some penetrating epoxies.

As far as using it for a glue, depending upon what you are glueing together and how it is claped, etc, you may have to thicken it, or you may not. Most epoxy glue joint failures are related to using too much clamping pressure. Epoxy requires moderte pressure, allowing some of the glue to stay in the joint. Cabinet grade joints are not friendly to epoxy glue joints.

I have used Raka on at least two boats and really liked it's quality. I have never had a glue joint problem other than the rubrails that I used too much pressure on. Even those opened up only a small amount and was easily repaired. After the minor repair, they have held for three years with no sign of opening up.

At Devlin's, we are using MAS and it is very comparible to Raka in viscosity. In cold molding the plywood, we don't thicken it at all. Staple in place, let cure, remove staples and move on. No problems at all.

[Frank Hagan]

Very nice, Barnacle Jim! It is really coming along, and looks great. What is the design? Looks like a friendship sloop inspired design (like the Weekender!)

A local choice for epoxy is a good one, since you save on shipping. I used RAKA and liked it better than System Three, but that might have been my "experience level" when I tried the kit from System Three. The good thing is that we have a lot of vendors to choose from. I call RAKA a medium bodied epoxy; I actually found the sample of MAS I used to be extremely thin, like water. Yet you found the RAKA to be too thin, and Jake says the MAS has the same viscosity as RAKA (and he really should know, he's sanded both a lot more than I have.)

[Charlie Jones]

I've found MAS and RAKA to be almost identical in viscosity and characteristics. I've used quite a few gallons of each and would have no hesitation on building a customers boat with either..

THe one BIG difference I've found in the epoxies is the cooler weather characteristics. MAS and RAKA both cure extremely slowly in comparison to WEST when the temps are under 60 degrees. Particularly so when it's in the high 40's-low 50s.. I've had both of those take three days to cure to a working state, while WEST can usually be sanded in 24 hours. So I keep WEST around too, for those times when I HAVE to keep going..

[Barnacle Jim]

Ahoy,

Thanks for the helpful comments. I'll try to answer what I can, and maybe some folks out there will be able to offer some fresh insight. Let's look at epoxy first and some of the problems we experienced

[capt jake]

When I added silica to the mixture (to thicken the epoxy), the mixture became the proverbial consistency of peanut butter. We were using the mixture to make a cove at the keel and bottom hull juncture. The thickened epoxy would sometimes hold the radius shape, and sometimes not. Sometimes, here too, we had the chewing gum problem. I do not know what I did right. I do not know what I did wrong.

One thing I recently learned is NOT to work the thickened epoxy any more than absolutely necessary. It is kind of like concrete in that the more you work it the more fluid it becomes. If you can gob the thickened goo into the intended area and squegee it ONE time, you will see better results. Joel makes it look easy. ;) :roll:

We mix with graduated cups. Though it is important to have the right ratio, most of the 2:1 is forgiving to a point.

The thing I don't like with West is the 5:1 ratio (I tend to forget where I am at) and I think it is over priced.

Charlie may very well have a point on the temperature and curing. I have always had the good fortune of having at least a bit of heat to keep on the curing epoxy.