Replicating S&G panels

[David Geiss]

I am a first time S&G builder...I know, it's cheating and not "real" boatbuilding (it's a set of amas I'm making). I have two panel shapes and have spent time to make both templates from 1/4" luan.

Any suggestions as to the safest method of routing the 4mm sapele into the panel shapes. I have 4 panels of each shape and as much as I enjoy hand planing, I think template routing would be faster and more accurate. I have a router table and handheld but not alot of extra hands around.

All insights appreciated! redface.gif

[capt jake]

First off, S&G doesn't require a precise fit, thus if there are any imperfections, that is OK. In reallity, a little gap is a good thing as the epoxy is able to 'key' into that crevise.

Setting a circular saw to a shllow depth allows one to make some pretty tight curves.

With that said, if you insist upon patterns, I have had fair luck with teh thicker double sided carpet tape to hold patterns in place. You can't apply a tremendous force to the pattern or it will shift. A spiral up-cut pattern bit works the best for me (if you can find them). The flat cut bit don't like to 'cut, while they do work well for a final 'trim' of the piece.

Good luck!

[David Geiss]

:D Thanks Capn Jake. I figured a luan pattern would be a decent time saver. Got the picture. What's your thinking on whether it makes sense to duct tape the outer seams while I'm making the fillets? Maybe I should say "epoxy filays" to make it sound tastier.
Have a good day!

[capt jake]

What's your thinking on whether it makes sense to duct tape the outer seams while I'm making the fillets? My opinion only (as you will get others) is to not bother with the tape. The only drips you will have is the intiial un-thickened epoxy. When you start to apply the thickened epoxy, your drips will not happen, though you may get a little 'ooze', but that is easily dealt with after the fact.

[JimD]

First off, S&G doesn't require a precise fit True if you're painting the boat but if finishing bright any small gap will show up and look bad.

[John Turpin]

I duct taped the seams. After putting all that effort into making "perfectly" thickened filler, I didn't want it just squishing out my "non-perfect" seams. I made my kids do it.

http://www.stratinsights.com/twopaw8/IMG_0926.JPG

[David Geiss]

I used the circulaw saw with the blade barely exposed and it's real accurate. I think I'll use double sided tape to marry two panel blanks and then pencil the panel shape on the top using the template.

I'll use the circular saw to get out the basic shape and the take Capn Jack's advice on a spiral flush bit for the final trim. For that, any proble using hot glue (in lieu of double side tape) to marry the template to the panels one at a time for trimming?

Appreciate the posts.........watch those child labor laws on putting those kids to work......they have access to all kinds of legal representation these days!

[Billy Bones]

Originally posted by David Geiss:
For that, any proble using hot glue (in lieu of double side tape) to marry the template to the panels one at a time for trimming?

AAACK! Hot glue is based on sillycone and will prevent any future adhesion by paints and epoxies in those spots.

[David Geiss]

Billy Bones...sure glad I asked. Too soon old...too late smart!

[emichaels]

Originally posted by David Geiss:
I am a first time S&G builder...I know, it's cheating and not "real" boatbuilding (it's a set of amas I'm making). redface.gif If you end up with a boat its real boatbuilding. One should not sell any effort short as long as one moves forward.

[Chris Ostlind]

David,

You can easily produce duplicates of the primary panel with double sided tape and a router with a flush cut trimming bit mounted with a guide bearing.

Rough-out the second panel, double stick it to the template panel and use a router table with a guide bearing on the trimming bit. If you're really steady with your router, you can also hand hold it and just follow the template without the rough cut stage.

The template panel will have to be smooth on the edges or you will replicate the irregularities in every way.

If you make the templates from nice, substantial stuff like MDO in 1/2" or 5/8" you'll be able to build the same amas over and over. Store them carefully and don't mash the edges.

Chris

[David Geiss]

Chris...thanks for the post. I think thicker MDO would have been a lot better than 1/4" luan but luckily I have no voids on the template edges and I have been able to plane nice fair surfaces. Yes, I can see these templates getting chomped, knicked, mashed, or whatever pretty easily. It occurs to me that going with the thicker more substantial MDO for templates would yield a better bearing surfcace for the bit bearing.

I'd have to pay a royalty to build more than one set and I have a feeling one set will keep me busy. My comment about this "not being real boatbuilding" is the juxtapostion between this experience and building a skin over frame kayak where I created everything from the keel up.

On the CLC plans, I think the data was "dead on" for making the panels but somehow getting boatbuilding plans without body and plan views felt odd.....anyway, John Harris was good enough to print out a body and plan views so I can devise bulkheads anywhere along the hull. I'll be needing to do that because I'm utilizing an open canoe as a vaka. Due to its configuration, the 48" fore/aft spread between the akas is insufficient.

It's a new to me to be working sapele. Have to say that buying it sight unseen from Harbor Sales in Baltimore has truned out great (delivered right to the door and each sheet cut in as many pieces as desired for $2.95 per sheet). It's the Shelmarine brand and, although it seems pretty tough on edge tools, it's real consistent throughout.

Best,
David

[RodB]

Maybe I'm missing something here...I can understand making a template when you need to make lots of copies... but it is so easy to draw/outline a panel shape and cut close to the line with a good circular saw (worm drive is better yet as it has a self gyro effect with motor and blade spinning it two separate planes), then use the good old low angle block plane to go right to the line. If making two of one shape, c-clamp them together and make two at once. The smartguide table or some similar cutting table in very nice to use.

Granted, pattern routing with a bottom bearing trim bit is extremely accurate and slick...but I could get two copies of two separate panels done in no time by just cutting and planing to the line...with plenty of accuracy and clean edges.

I would think that you could draw out your patterns and cut and plane ...and be done with two copies of each shape... in less time than it took you to make the pattern.

Since you already have the patterns, I would think hand routing with a top bearing trim bit would be the best way to approach this (I like a D-handle router). Just make a spacer to keep the workpiece up off the table enough to clear the router bit, (could you use sheetrock screws to secure the work piece with template and spacer?).

RB

[ 10-26-2005, 05:22 PM: Message edited by: RodB ]

[pjwalsh]

On Hot glue - formulations vary a lot depending on the application but it is not based on silicone - usually an ethylene-vinyl acetate copolymer sometimes with reactive polyurethanes mixed in. In any case it probably will interfere with epoxy bonding, but if the affected area is only near the root of the fillet, it will be small and will make little difference in the strength of the joint. Still I think the duct tape is a fine approach. I have used plastic cable ties and copper wire through small holes with success also.

**edit: whoops - guilty of not reading the thread carefully - I see you are using this to fasten patterns to your planking stock. Billy bones is probably right that this could make it difficult to paint over.

[ 10-26-2005, 05:11 PM: Message edited by: pjwalsh ]

[Billy Bones]

Well thanks for that clarification on the chemistry of hotglue pjw. In any event it will play holy heck with any finish/topcoat/other adhesive you use subsequently. It seems to be very good at getting into pores and staying there, causing fish-eyes and so on. It can't be just sanded out lightly and gone over.

Which is rather a shame because it is so handy to use.

[George Roberts]

I use hot glue for many tasks. I never have a problem with finishing over the glued area.

4mm ply:

Tape the 4 layers and template together. Start routing. When you cut some tape, replace it behind the router. Continue until done. (Small clamps will work in place of tape..)

[JimConlin]

If you're making four of each part of say 6 mm sapele ply, template routing is nice, but a mid-size (2hp) router would choke on that thickness. I'd assemble the stack of template and the four blanks with carpet tape, cut 'em 1/8" strong with a jigsaw or bandsaw and trim with a top-bearing router bit.
The question of how to marry stitch&glue panels has been thoroughly treated in the past. Someone will fine the definitive threads for it.

[David Geiss]

I like Jim's idea and I'll rough the panels out in stacked fashion on the bandsaw. Got this afternoon a straight flush trim bit for the touch up. Those spiral flush bits were real pricey.....like in the $120 range. The newer Amana spiral flush bits (Ultratrim?) have two bearings and look sweet. Like I said, I'm making just a hanful of panels here.

Laying out the templates did not take too long but I think it was worth the effort since I am making four panels from each template and no need to loft two pairs.

It's nice to see those nice curves take shape!

[plyboat]

David
Just stack your plywood and cut them all at once with a skill saw and for areas with a lot of curve you can always use a jig saw if you want, but I have never cut a panel with anything other than skill saw and where there is a lot of curve just butcher it outside your line and clean it up with a power plane. With all the panels stacked you can fair them with a block plane and they are all the exact same.
---Joel---
boatbuilder.org

[David Geiss]

Ouch....double sided carpet tape can rip the face veneer right off luan! On the issue of templates, definitely would go with like 1/2" sugar pine or MDO next time. Luan, flimsy as it is, will get me through on this one though.....

On the issue of routing, yeah it's accurate but it's a lot of concentration for multiple short runs between clamps to the table.
Think that sawing rough with a shallow set blade on a circular saw and then having at it with hand plane is overall simpler. LIve and learn.

Those worm gear 4" circular jobbers looks sweet though.............I'll just get through this one with my 7incher....... :D

[RodB]

I'ved used my Makita hyphoid with a good 60 tooth carbide crosscut blade... to cut out panels with great control...and then planed to the line, quick and sweet...

RB

[JimConlin]

Ouch....double sided carpet tape can rip the face veneer right off luan! On the issue of templates, definitely would go with like 1/2" sugar pine or MDO next time. Luan, flimsy as it is, will get me through on this one though.....
If you do the whole set of parts, it only needs to be peeled once.


On the issue of routing, yeah it's accurate but it's a lot of concentration for multiple short runs between clamps to the table.
Use a router table.

[capt jake]

I have been using the PC Saw Boss 6" for some time now. Very accurate and easy to control, as it doesn't weigh a lot. It's a side winder but the blade is on the right. I use it often for outside trim on houses and such.

[epoxyboy]

Just use one of those $12 hardpoint handsaws to cut your panels - they rip through thin ply like you wouldnt believe AND you can cut right to your pencil line AND you dont get a wobbly line like you do with a jigsaw. One thing that really helps with the stitching is to put a bevel (nothing fancy, just a couple of passes with a plane) along the edges of both panels where they get stitched together, otherwise you wind up with the two sharp corners trying to jump over each other, and always the wrong way.

Pete with a fully framed Welsford Pathfinder :)

[David Geiss]

Had I used thicker template stock most definitely would have used the router table....with the luan and 4 mm ply, it just flops around too much to do solo, even with infeed/outfeed stands.

I was thinking about those mating surfaces when I stich this all up and the post about the bevel is the antidote!

It may be quick and dirty boatbuilding, but S&G takes time nonetheless. I'm learning as I go and it's fun!
Thanks to all who have contributed. :cool:

[Paulyboy]

Originally posted by epoxyboy:
Just use one of those $12 hardpoint handsaws to cut your panels - they rip through thin ply like you wouldnt believe AND you can cut right to your pencil line AND you dont get a wobbly line like you do with a jigsaw. One thing that really helps with the stitching is to put a bevel (nothing fancy, just a couple of passes with a plane) along the edges of both panels where they get stitched together, otherwise you wind up with the two sharp corners trying to jump over each other, and always the wrong way.

Pete with a fully framed Welsford Pathfinder :)Remember to make sure the panels are either face to face or back to back when cutting, otherwise, you'll have 2 lefties or 2 righties. Especially important when you plane the bevels, going at each panel like they are.