Woodworking 101 thread. Beginner needs help!

Sorry, Aus standard is actually 72 hours.Jeff.

 

Read the whole thread, some comments stay:

-to my opinion, this is still woodworking. Only after you glass it, it becomes a composite matter. Luckily, a lot of woodworkers even in the composites section.

-about scarfing a lot has been said, and I do not have anything to add, besides that okoume is a light, but slightly brittle wood, that askes for really sharp tools. You can see this in the part that looked OK until you touched it with the power plane. Chunks of wood just got ripped out.
I have had a couple of boats (Flying Junior) that were made from this wood. It is a nice type of wood, but actually does not like feather edging a lot. I will come back to this later in my post.

-The defects seen in your pictures (split veneer) should not happen. as you will be working wth epoxy, it is not a big deal, unless you want a natural finish. (you told the stuff comes from Greece. I guess they used the missing splinter for firing the electricity plants, now that the country is as good as bankrupt... (joking guys, just joking... )

-About your construction method: How many layers of wood are you planning to glue together, to reach the final thickness of your skin? I ask this, because you could get away with butt joints, which makes your life easier.
All construction I have done with okoume were butt joints, usually 4mm thickness. Decks of racing boats we made from a base layer with a butt joint on a bulkhead, the top layer went on on a different spot. The left sheet was clamped in place, the right sheet was clamped with a 6mm gap between the sheets, and a router with 8mm bit was run in between, along a straightedge, taking 1mm off of both sheets. Then the right sheet was shifted towards the left sheet, to make a perfect joint. Everything was liberally coated with epoxy, and glued together. No pain, and never problems.

 

Saw A Pattern To The Destruction This Morning!

Ok, I'm going to try to address all the helpful replies. First, let me just say a very hearty thank you to everyone who has replied to this thread. I've studied every response and thought carefully about them.

Plywood Quality

I had already put up the link to the supplier. Charly and I used the same supplier and ordered the 3mm Okoume, of which, they only have one grade. From what I have learned, BS1088 Okoume ply does not exist in 3mm because the BS1088 standard specifies a minimum layer thickness of 1mm. Since you can't have glue in there with 3 layers of 1mm plywood and still have the sheet be 3mm, there is no way to have a BS1088 plywood. My plywood, however did not have the same stamp as Charly's. His looked like this:



Mine, which I haven't taken a picture of yet, says, "BS6566, Boulter Plywood." I had asked Chris Boulter for the Lloyd's Certification number for this plywood and he gave it to me. It's the same number as the stamp on Charly's plywood. I have asked Chris in an email why my stamp is different than Charly's and am awaiting a reply. Supposedly, this plywood is made to the BS1088 standards, although no 3mm can be called BS1088 as per the specification.

As to the color of the glue, no sample of plywood I have seen has had any dark glue in it. None. I have samples from a few different vendors and of varying thicknesses. All BS1088 (except one) and none had dark glue. Is this a problem??

I boiled the plywood 4 or 5 times and threw it immediately into the sun in FL. It didn't change it at all.

Laminate separation

Ok, I think I know what's going on here. You are looking at the plywood as if it's thicker. It's 3mm. There are only 3 layers per sheet. The separation you picked up (very good job noticing by the way) is the warping of the plywood in general. I will address this at the end of this post. I found a pattern with the warping and chunks taken out! :idea:

Grinder (ThomD)

ThomD: Thank you very much for this detailed reply. I used a standard grinder that "said" it was 0rpm-whatever, but it seems to only go fast. I also used that same sanding disc set you mentioned, however, I used the regular stiff rubber backer and not foam. That could be some of the problem. I used 50 grit.

The Boat Plans

The plans specify (strongly) a 12:1 scarf (and strongly specify 1.5" here) for this boat. They plans also strongly specify scarf joints over butt joints for strength. The boat is built to ABS Offshore Racing Yachts specs and is US Coast Guard inspection passable (several of these are inspected vessels). Deviating from the designer's plans gives me great anxiety. I'm not sure it's a good idea to deviate from the specs. This boat is very carefully engineered to be very light and very strong. Shouldn't I stick to the plans?

I Noticed a Pattern to the Destruction!!

In the pictures, below, please notice what my stack of 3mm looked like this morning when I went to try some of these ideas. The warps are still there, but they got a lot worse overnight. I can't get it to sit down at all. I unclamped it and smoothed it toward the edges, sat on it, laid on it, did whatever it took to get them down, then tightened the clamps. The minute I got up off it, it went back to what you see in these pics.

Charly, how do you use drywall screws to hold the warps down on a surface you are sanding? Sorry, I'm not understanding that tip, but want to hold these down...

The pattern I noticed was this:

The chunks taken out are on *uphill* sections of a warp. As in, when the warp is going from nice and flat to severely warped, this is the exact spot both the grinder and the power planer took chunks out. They didn't rip to top of the warp out, but ripped out the "hill" of the warp as it increased from left to right or right to left. See the extra pictures below, where I tried to show how the chunks are in very specific places, if you look only at the level of warping.

How can I get this warping out for another try??

 

How well is the back part of the stack supported?
If it is drooping, it will try to open up the front edges.

 

Decided to give it a try this morning again... f'd up even more. The planer seemed to be doing a great job, until I noticed that every pass was making a jagged edge on the scarfs. Also, it took out small chunks again, no matter if I held it at 0deg, 30deg or 90deg. It did this only where the warp transitions from no warp to huge warp- on the hills.

I took out an orbital sander and smoothed some of the jaggedness out from the planer. It's still jagged, but at least it's smooth.

This is getting very maddening. It's a simple part of the boat build and I can't get it.

So do I go get foam pads and try the 9,999,999 RPM grinder some more?

Do I get a belt sander?

Buying more and more tools all the f'n time that I don't need isn't helping my very meager boat building budget!

I'm pretty against the router rig thought because I don't have any steel, I don't have tools to work steel and I don't want to pay someone to do that for me. I'm working on a *very* limited budget.

What should I do?? I don't know which replies on the forum will work, which won't and which will be the most simple/economical and easy to do.

 

It's not supported too well at all, actually. I have been wrestling with that. The back end of the stack goes up in a reverse, updside down stair step, opposite of the side I'm working on.

It would appear there is no way to support that reverse stair step with the 2x4 lumber I am using below the stack of plywood for support.

Should I cut some kind of long wedges, maybe 3 of them, out of a 2x4 and try to shore it up some more on the side opposite that I'm working on to try to give the stair step on the other side some support?

 

Ok... you got to wrap it.. Take a heavy >= 0.20mm plastfoil (used in buildings moisture isolation), put it under your ply pack and fold it over the pack. Tape the seams and leave it for couple of days. Then the moisture content of the pack should be even. Opening the pack you have only limited time (few hours maybe?) to work before it starts to warp again.

 

If you have a Slilsaw, buy a fine-toothed blade for it and build an attachment out of 2 x4's for the base, per the pictures below. The attachment rides on top of the plywood, and the blade cuts the bottom.

I cut 2 layers of 3/8" plywood at 8:1 using mine last month. Change the angle and you can cut 16:1, but you won't be able to do many at a time.





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Try fewer sheets at a time, say 10. Get the stuff off the concrete floor (high humidity) and onto a sheet of plywood sized temporary workbench where you can easily work. Clamp a 2x6 or a 4x4 across the top to keep pressure all the way across the stack.

 

Ok, I'm going to give this one a try first.

I need a temporary work bench anyway for many reasons and distributing the clamping out over the whole sheet makes a lot of sense.

Maybe (as many have said), it's just not supported well enough.

 

Maybe I should have read the whole thread more carefully; I didn't realize the wood was in contact with a concrete floor. There's definitely a possibility that it's warping simply from absorbing moisture.

I agree with doing fewer of them, and clamping them down thoroughly. You might even screw the stack temporarily to a work table, with screws just beyond the scarf.

 

The wood is not in contact with concrete. It's on 2x4's above the concrete.

 

I kinda liked Troy's idea
long as you dont go chopping your fingers off having the wood clamped down and then cutting down the length of it like that should give you at least a straight scarf
my take is I'd set it up so I didn't have to slice sideways like that but his idea is a good one
skill saws are brainless and when your just starting out brainless is best

best of luck
B

oh
dont clamp it to hard or that saw might just come back at you in a hurry
just enough to hold it straight

and keep your other hand out of the way
and dont cut at pecker height either or your wife might come up with a few more witticisms for ya

 

close to the concrete still makes a difference
pain in the *** as it may seem that ply should be up off the floor on a nice flat rack of some kind

cheers
B

 

A level workbench high enough to work comfortably is a very good suggestion and will speed your progress while adding years to the useful life of your back.