SeeYou1901) They vastly increase the surface area for wood glue to adhere to.
A biscuit adds about 2 square inches of surface area for your glue if you count both sides. I'm not sure that qualifies as "vastly" when a 3x12 splice plate would add 36 square inches.
SeeYou1902) They help keep things aligned.
Biscuits by design only help in alignment vertically. They are made deliberately with slop horizontally to allow easy assembly. As long as your roadbed sections are the same thickness, you don't need this alignment help.
SeeYou190This is extremely strong and rigid. The biscuit is there to enhance the joint, it is not the joint.
If you do some objective testing, you'll find that a splice plate provides a stronger result. Here's an easy test - take a 5-gallon bucket and loop the handle over the unsupported end of a piece of roadbed. Gradually fill the bucket from the garden hose (how convenient you're working outside). See which joint holds the most water.
I have fun re-inventing the wheel from time to time as well, so if that's fun for you by all means enjoy it. Just don't fool yourself into thinking that you've invented something superior to what thousands of other modelers have been doing for dozens of years.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
As a carpenter and cabinet maker, I have just been quietly watching.
Biscuit joints are most commonly used at cabinet corners, edge to face joints.
We do use them on some edge to edge joints with demenisional lumber, not plywood, and mainly for alignment, not strength.
Personally, I would not bother using them in plywood edge joints.
Kevin, your workmanship is very nice, just seems way over built, even to my climb on standards.
More later when I get home from work, we are busy remodeling a $700,000 home.
Sheldon
Biscuits do two functions for me:
1) They vastly increase the surface area for wood glue to adhere to.
2) They help keep things aligned.
.
The drawing below shows how I approach the areas where two sections of plywood subroadbed are attached to one another. There are double 2 by 2 cleats on a riser, and each piece of plywood is glued and screwed to its own cleat.
The biscuit is in between the two pieces of plywood at the butt joint, and glued throughout. The biscuit is shown in red in the picture.
This is extremely strong and rigid. The biscuit is there to enhance the joint, it is not the joint.
Here is what it looks like on the layout.
-Kevin
Living the dream.
rrinkerbiscuits are I suppsoe as good as anything
Not based on my experience.
And BTW, I've always liked having my splice plates on top of risers where possible.
Day 15, Post 1:
I am working on control panel graphics right now. I am working with Power Point, and it is a great tool to use.
This is the smaller panel so far:
gmpullmanThat's good advice I used a saber saw/jig saw and cut slices either side of the roadbed a good 24 inches back from the edge where the joint would fall. Screwed & glued the splice plate while flat then gently began my rise,
Thank you all for the Happy Birthday wishes. I had to work (somwhat) on my birthday, but it was fixing things, and had a really good day.
The joint is not on a grade, in fact there are no grades on this segment.
There are only planned to be two grades on the real layout, so we will not have too much to worry about in that matter.
rrinker Actually I would work hard to make sure the start or end of a grade doesn't fall over a joint of any sort, biscuit or splice plate.
Actually I would work hard to make sure the start or end of a grade doesn't fall over a joint of any sort, biscuit or splice plate.
That's good advice
I used a saber saw/jig saw and cut slices either side of the roadbed a good 24 inches back from the edge where the joint would fall. Screwed & glued the splice plate while flat then gently began my rise, about 1.4% grade, AFTER the glue set for a day or so. I used shims like you would use to set a door frame driven in at the very beginning of the rise, too. Same thing at the top, the "crest" of the grade falls somewhere along the solid plywood, never at a joint. Sort of "Cookie-Cutter" style.
Another point of the biscuit joint, plus the three-piece riser as shown in Kevin's photo it that there is limited "tensile" strength there. When the wood shrinks the pulling stress may be enough to break the biscuit joint and pull away the blocks on either side of the riser.
A laminated splice plate below the roadbed joint should be at least 12 inches or more.
Happy Birthday, Kevin!
Cheers, Ed
Actually I would work hard to make sure the start or end of a grade doesn't fall over a joint of any sort, biscuit or splice plate. Even with a splce plate joint, unless you use a really long splice plate, is likely to end up with a slight kink instead of a smooth tranistion. And with cork or other material on top, the gaps should never line up with the subroadbed gaps, but also there shouldn't be a joint between cork sections at the curve transitioon point - vertical or horizontal, actually, for the smoothest fit. It's the little things, but you can't build bulletproof track if the underlying base isn't equally bulletproof.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
SeeYou190 it is my birthday!
Happy Birthday Kevin!
Question - where you have the biscuit in one side of the wye in the subroadbed, is there going to be a grade on one of the two routes? The reason I ask is that, if you are planning on starting a grade where the biscuit joint is, you are asking for problems. If both sides of the wye will be flat or on the same grade then the joint will be okay, but if one side goes up or down it will be highly unlikely that the joint will form a smooth transition into the grade.
If I can offer my worth, that is not a location for a biscuit slice. A single biscuit just won't have any strength. You would be far better off, grade or no grade, to do what Randy suggested and take a scrap piece of plywood and screw and glue it to the bottom of the subroadbed. You want to make the splice piece extend 8" - 10" on either side of the subroadbed joint. If you want to prove me right, take the single biscuit joint and bend it over your knee. I suspect that it will crack without a huge amount of force. The biscuit may not break but it would prove that the joint is very weak.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
rrinker...biscuits are I suppose as good as anything, but the 'usual' way to do it is take a scrap piece and use it as a splice plate...
I agree, Randy. When you're building a layout, there's always lot's of cut-offs and left-overs laying about, and a splice plate doesn't require any special tools - something with which to drive a few screws is about all that's needed.
Biscuit joiners would, however, be useful for helix construction, and, I suppose, if you have the equipment, might as well use it.
Wayne
I'm wondering about making a solid connection between sections of the plywood subroadbed. Rarely see this done. Even a slight gap is meaningless, as the cork or homasote will be continuous over the gap in the plywood so it will have no effect on track alignment. Just but them up close and secure both sides of the joint area. If the joint happens in free space, like betwene risers - biscuits are I suppsoe as good as anything, but the 'usual' way to do it is take a scrap piece and use it as a splice plate. One somthing like a helix where every bit of clearance helps, the double thickness may be a problem - in which case the biscuit joint is a perfect solution. But where it doesn't matter and will be hidden under scenery....
Day 14, Post 1:
Went to work today duplicating my efforts from yesterday, but on the upper level where there will be two bridges and a turnout.
I managed to install the upper risers.
I also put in the first piece of plywood subroadbed. You can see another joint, this time more complicated, where the pieces nees to be connected.
I intended to get more done, but I had a bunch of work stuff that ended up interfering with plans.
And... it is my birthday! How dare work come in between me and my hobby on my birthday?
Oh yeah... I have bills to pay! That is why.
Lone Wolf and Santa Fe I would advise you to run the electrical conduit underneath instead of on top of your framing so that it's not covered up by scenery.
Yes, yes, yes.
I have already realized the mistake of running the wire over the stringers instead of under them.
That is the great thing about experimenting like this. When I do build the actual layout I will make sure it is easier to get to when completed.
SeeYou190
You made a good choice not to use Romex wire. It is for use inside of walls and can easily be damaged or ripped out of receptacles. Plus you have to hammer staples into the frame to hold it in place. However I would advise you to run the electrical conduit underneath instead of on top of your framing so that it's not covered up by scenery. Also you should use regular 1/2" flex so that if you ever need to replace a wire or add another one you can. That is one of the advantages of conduit. And if you do replace or add wires you will need to shake it around a little to help you fish it through. That little skinny stuff you are using is for feeding a single light fixture. You have no room for future expansion using it and it is so tight that it is really hard to pull wire through it. Solid #12 wire is the best to use. And you are correct using 15 amp receptacles on a 20 amp circuit because you are not going to use a single device which is over 15 amps. If you plan to use a high wattage electric heater or air conditioner then you need to add another circuit. If it's over 15 amps that is when you use a 20 amp receptacle.
SeeYou190Dave, In your picture the Homasote looks to be about one inch wider than the cork roadbed. . I was planning to cut the Homasote to the same width as the cork roadbed. Is this a bad idea?
We cut the Homasote about 1" wider than the cork so that when we bevelled the Homasote we could make the trackside ditches as deep as we wanted them. The depth of the ditches will vary depending on where they are on the layout. If you don't need to model deeper ditches than you can cut the Homasote to the width of the cork. However, if I were you, I would cut the Homasote the extra 1" wider just so you have the option of making deep ditches easily if you want. Bevelling the Homasote was easy with a standard utility knife (box cutter to you guys south of the border).
Day 13, post 1:
Began work on the lower level of the trackage today.
I first laid out the track on the foam board I am using to make templates. I actually prefer to use sectional track when possible, I know my curves are all exactly 24 inch radius, and straights are good. I also try to never have more than 18 inches of straight track. To me, trains look best when they are going through curves.
I had to add a crossmember on the right side to support the lower track in the area after where it made the curve.
I transfered the foam board templates to the plywood and cut out the sections. I chose to use 7 ply 3/4" thick plywood for this project.
I really do not know much about plywood, so I hope this will be good enough.
I split the plywood subroadbed into two pieces to cut down on waste and make the most of the material. I made this double cleated riser for where the plywood joint would be.
This area of the curved track was further reenforced with a 1 by 2 on a 45 degree angle between the two risers.
When I joined the plywood subroadbed pieces together I used biscuits and wood glue in addition to wood screws to secure and strengthen the joint.
This is all really going well at this point.
Dave, In your picture the Homasote looks to be about one inch wider than the cork roadbed.
I was planning to cut the Homasote to the same width as the cork roadbed. Is this a bad idea?
SeeYou190New question: What is a good way to attach Homasote to the plywood subroadbed?
I'm going to suggest that you use drywall screws only. The glue won't hurt anything but you won't be able to lift the Homasote up if you ever need to. One example where you might want to lift the Homasote is to create a transistion from the mainline down to a siding or a yard where the rails are below the height of the mainline. Most people sand the cork roadbed to taper it but our club found it much easier to cut the Homasote along the yard/siding track for about 15" from the mainline. We then used cereal box shims along the cut to elevate the end of the Homasote to where it meets the mainline. The result was a nice smooth transition.
One small point about screwing down Homasote that has been cut cookie cutter style to match the plywood sub-roadbed. Keep the screws under where the cork will be. We made the mistake of putting the screws outside of the cork, but when we went to bevel the Homasote to create deeper ditches we had to move most of the screws. That was a real niusance because the track had already been laid.
You can see the bevel here:
ATLANTIC CENTRALGlue and drywall screws
Is there a special glue to use, or one that works better than others?
I would assume white glue or wood glue would be OK, but would Liquid Nails be better?
SeeYou190 hon30critter Sorry, I can't find any pictures that show the V shape. Dave . Thank you Dave. . If I do not like the results of the knife blades, I will look for blades like you are describing. . On another note: . New question: What is a good way to attach Homasote to the plywood subroadbed? . -Kevin . -Kevin .
hon30critter Sorry, I can't find any pictures that show the V shape. Dave
Thank you Dave.
If I do not like the results of the knife blades, I will look for blades like you are describing.
On another note:
New question: What is a good way to attach Homasote to the plywood subroadbed?
Glue and drywall screws
DoughlessAs far as plywood, I picked up some Sande Plywood at the orange store, as I was apparently mezmorized by its beautifully smooth and uniform surface at the time. Got it home and realized it has about the same density as balsa wood.
I saw some of this plywood at the Cape Coral Home Depot.
The finished surface is great, but I saw what you meant about the light weight and density.
hon30critterSorry, I can't find any pictures that show the V shape. Dave
SeeYou190Dave, What do you mean about not haveing any teeth set? . I just ordered six knife blades for the jig saw. These have no teeth. Are these what you are describing?
Hi Kevin,
No, they are not knife (smooth) blades. From the side a hollow ground (also called a 'planer') blade looks pretty much the same as any other toothed blade. However, when you look at the teeth themselves, they are not bent to the left or right to expose the tips of the teeth like a blade with 'set' teeth. Instead the blades are ground so that the back of the blade away from the teeth is narrower than the tips of the teeth. If you were to look from the top down the cutting part of the blade is 'V' shaped.
A hollow ground blade cuts differently from a blade where the teeth are bent to the side (set). When a tooth is 'set' it results in the wood being torn away leaving a rough surface. The hollow ground teeth cut with both the tips and the sides of the teeth. That has the effect of planing the sides of the cut instead of tearing it. The result is a very smooth cut. The taper prevents the blade from jamming in the cut. A blade with set teeth where the teeth have lost their set binds in the cut.
I'll see if I can find a picture. Sorry, I can't find any pictures that show the V shape.
Day 12, Post 3:
I made a template for the shape of the river. I used black foam board to make the template.
I used the template to transfer the shape to a piece of 3/8 inch plywood that will form the river bottom. I added about one and a half inches to wach side for the scenery to attach to.
After the river bottom was in place, I trimmed the fascia board to be flush with the river bottom.
Now it seems that every little bit of progress is making this thing really start to look like something.
Day 12, Post 2:
I finally am installing the track supports.
I fabricated the risers from 1 by 4 and attached a 2 by 2 cleat to the top. I was careful to keep everything square durting the assembly.
The large bridge will cross the river at a 10 degree angle to the backdrop. I made this wedge piece so I could attach the riser at the bridge end at the correct angle.
The riser is attached to the benchwork.
Finally, after another riser was installed, the bridge is looked at in the correct position.
Back to work...
SeeYou190I thought the offet from side to side was called "kerf" or something. Would I look for a blade with zero kerf, or something like that.
Well, actually the kerf of a blade is the slot that the blade takes out,
I think what Dave suggest would be a thin kerf blade.
You can tell when the teeth are out of set, and the kerf is narrower, as the blade binds easily.
Mike.
My You Tube
Day 12, Post 1:
I thought the offet from side to side was called "kerf" or something. Would I look for a blade with zero kerf, or something like that.
I am trying to remember back to the four years of high school wood shop I took to remember what Mr. Porta taught me.
It turns out you can buy premium lumber at Home Depot in Southwest Florida, just not the one that is closest to my house in North Fort Myers.
I went to a newer, and larger, store in Cape Coral, and I found Oak, Poplar, Cedar, and very nice looking pine. I bouight several pieces of the pine.
I will post anotyher update later today.
ATLANTIC CENTRALI'm pretty sure he means teeth with no offset from side to side, the blade is smooth along its side.
I didn't know you could buy such blades. I know it happens to a blade after alot of use and abuse, but I didn't know you could buy a blade with no set to the teeth.
Maybe the reverse tooth blade would work too. Cuts on the down stroke.
SeeYou190 Dave, What do you mean about not haveing any teeth set? . I just ordered six knife blades for the jig saw. These have no teeth. Are these what you are describing? . -Kevin .
Dave, What do you mean about not haveing any teeth set?
I just ordered six knife blades for the jig saw. These have no teeth. Are these what you are describing?
I'm pretty sure he means teeth with no offset from side to side, the blade is smooth along its side. Most blades today have the teeth "kicked" left and right, you have to look for the older style with smooth sides.
I have cut homasote with that kind of blade for decades. Never tried the knife blades.