Fillet size for Passagemaker

 I am starting to assemble the center seat..daggerboard box, seat and center bulkhead.  The directions call for 1" fillets.  What is a 1" fillet?    Is a 1" fillet an arc created from a 1" diameter tool or a 1" radius tool?    I want this assembly to be sufficiently strong but smaller fillets look more pleasing to the eye.

All inputs would be greatly appreciated.

Best regards,

Roger


10 replies:

« Previous Post       List of Posts       Next Post »

RE: Fillet size for Passagemaker

Looks like you need the handy dandy   Arc calculator

 

In the meantime, if the fillet is there just to support the glass tape, it can be pretty narrow, but if it's not going to be glassed it needs to be near the size of a piece of 45 degree molding with the hypotenuse being the specified width placed into the  joint so it can smoothly transfer the forces from one piece of wood to the next.

Have fun,

Laszlo

 

RE: Fillet size for Passagemaker

Great question!  I interpreted it as 1" radius for more coverage/bonding area/strength, so bought a 2" wide plastic spatula and radiused the corners.  They are kind of large looking on an EP, but I've dropped it twice off the sawhorses with no damage. It should look more in scale on a PM.  I plan on doing the same thing on my PM, although I may tape all the seams instead of letting them fade tangent to the plywood.

Here's my writeup:

http://www.midnight-maker.com/#!Eastport-Pram-Build-6-Progress-as-Promised-–-It’s-All-Coming-Together…/c1kw6/55b556aa0cf286eab02cd111

RE: Fillet size for Passagemaker

Nice write-up, Skully .

For all thick fillet makers, you can completely avoid the heavy sanding by painting the fillet with a chip brush dipped into unthickened epoxy. It smooths that nasty grainy texture and evens the surface. It takes almost no time at all to do and saves a ridiculous amount of sanding. All that's needed is a very light touch up with #220 or finer and you're ready to varnish.

Have fun,

Laszlo

 

RE: Fillet size for Passagemaker

Laszlo literally has an order of magnitude of experience over me. I hadn't heard of the "painting" of the "clear coat" of epoxy on top of the fillets when I built my EP, but that totally makes sense.  That's a very interesting concept which I may try on my PM.  I used the "smooth the fillet with a gloved finger dipped in denatured alchohol" method which worked amazingly well.

RE: Fillet size for Passagemaker

While we're on the subject, let's talk about masking.  On my EP, I only masked the fillet on the inside between the bottom and the garboard prior to glassing.  The way I determined the width of my unmasked area was I stuck my filleting tool into the intersection and marked where the radius touched the plywood tangentially.  I repeated this up and down the seam.  Based on the intersection angle, this narrowed or widened the unmasked area.  I then laid down my masking tape following those lines.  The idea was that this would make a smooth, straight fillet that faded to nothing at the tape.

The reality of the situation is that it also depends on how hard your press on your filleting tool, angle that you drag the tool, etc.  What I ended up with was a nice straight looking fillet, but for most of its length, there was a tape thickness deep shoulder of epoxy once I removed the masking.  This was very noticeable to the touch.  In my inexperience, I faired that down with denatured alcohol, but I think subsequent layers of glass and epoxy would've covered it.

Any suggestions?  I'm seriously thinking about taping all the seams on the PM because I want it to look more crisp.

RE: Fillet size for Passagemaker

���Good idea about using the tool to mark your lines. I wish I'd thought of that. In my experience, a true tape width of epoxy is not very noticeable. Easy enough to clean up with an emory board. You probably actually had more than a tape width. I have learned that if I run a plastic spoon down the tape on a fresh fillet, I can make the fillet edge truly only the thickness of the tape. The spoon neatly collects the extra epoxy. For me, learning "epoxy-working" is harder than learning "wood-working". Hooper Williams-Brevard, NC

RE: Fillet size for Passagemaker

You ever see how DIY painters spend lots of time and money masking? And how pro painters just get in there and paint. They're done painting before the DIY crew is finished masking.

Same thing with fillets. Lose the masking tape. Do exactly what you did pushing your tool at the correct angle with the right pressure. You'll get that nice fillet and and a ridge on each side. Grab a flat putty knife and scrape those ridges off. Use them for the next section of the fillet. Then, when the whole joint is filleted, grab your chip brush and paint the fillet with unthickened epoxy, as described above. You get a nearly glass smooth fillet with no shoulders.

And if you're going to put glass tape on the fillet, as soon as you've painted the fillet smooth, take your tape, roll it up and pour your epoxy on it. Squish it around in your gloved hand until it's saturated (no white fibers), squeeze out the excess and unroll it onto the fillet.

Smooth it in place with your gloved fingers and spread any excess onto the wood above and below the joint. Perfect fillet, no bubbles, no drips, no sanding.

That's how I'd do it.

Have fun,

Laszlo

 

RE: Fillet size for Passagemaker

���I'm sure what Laszlo's saying is correct. For me it's going to take more than one boat to develop that skill. I want the first boat to look good, too. Hooper

RE: Fillet size for Passagemaker

How about a combination approach then? Go ahead and mask and apply the fillet as usual, but just as soon as the fillet is down, pull the tape and paint the fillet with unthickened epoxy. That will get rid of that shoulder and give you a nice smooth fillet.

Friends don't let friends sand fillets, life's just too short for that :-)

Laszlo

 

RE: Fillet size for Passagemaker

���If you have to use training wheels, get them off asap. Hooper

« Previous Post     List of Posts     Next Post »


Please login or register to post a reply.