Rail band taper into nose/tail

[DublAK2]

I’ve only shaped 2 boards and I relied on Greenlight’s manuscript like a crutch. For anyone unfamiliar, they provide a PDF image for 2 rail styles showing you where to mark measurements at the 12” marks and wide point for a 2.5” board. Then they provide a chart according to board thickness to adjust the the rail marks as needed.

they also provide a chart for the measurements at the wide/thick point for alternative  rail styles (50/50, down rails, soft rails, etc.). However for the alternative styles they do not go into detail about where to go with the rail bands in the nose and tail.

I know a seasoned shaper can make the rails they want with their eyes and feel. However for a n00b like myself, is there a simple rule of thumb or mathematical factor for unveiling rail band measurements as they taper into the nose and tail?

[WideAWAKE]

I do t know of a mathematical way to create the transition (you can lay out marks to make a center tail shape - a nose and tail rail and connect them all though) 

once you do a few you can do it without laying them out. 

A quality plan shape will go a long way when it comes to cutting a rail. 

Before I was able to work them out from nose to tail I’d get my center where it needs to be then work them out towards the nose and tail  it’s slow but works.

If your planer doesn’t have on the fly adjustment then it’s difficult to go nose to tail with cuts because your depth is set. It’s all a matter of starting at zero cut and fading it deeper and then back out. 

visualize bringing your deck down to meet your rail apex (which when you are done with your rail should be it’s center apex and uncut) 

drawing them out will really help as well to give you a visual of what you are looking for before you start cutting. Don’t cut and hope for the best - have a plan  

Screens are not for shaping, just for blending the bands, my screen rarely touches the apex band, if it does it’s changing the plan shape. 

If you kick the board on its side in the racks it’s pretty easy to see rail flow when you cut your bands - you want clean consistand curves from nose to tail - no humps and bumps  

 

 

[DublAK2]

So I suppose eyeballing and finessing it is the way to go. I was hoping there was a cheat to make some guide marks in the nose and tail.

i have a non modified planer, but I will probably start in the center and feather out in either direction like you used to do, but with a surform for more control.

you make some crisp rail bands there feller!

[WideAWAKE]

You can definitely place some reference points along the rail line to connect the dots so to speak  

also a surform is not a bad tool to use when first starting. Long passes with varied pressure from nose to tail as if you were adjusting the planer depth. 

[DEADSHAPER]

Always put your desired bottom in before doing your deck.

A surform or sanding block can be used for ‘chipping’ the edge of the bottom rail line. A common practice for novice (and even more experienced) shapers is to fashion a little L shaped block of foam with a pencil in it to scribe a line before sanding in the edge.  You can then “raise” the rail line in the specific area you desire, like more “up” in the nose, and “down” in the tail. 

Once you have the bottom rail line, it comes down to shaping your top rail line to meet what you have done on the bottom.  Don’t ever do it the other way around, because you will find if you do that, you will change your rail line again when putting in vee or other bottom configurations as an after thought.  You will not have control of the end result in this sequence of shaping and more than likely, will not be pleased with the end result.

The top rail line is dictated by the angles of cuts you put into the foam, and even the sequence in which you do the cuts.  It will help you to envision the angles and what makes for “acute” or “obtuse” rails. Opt for obtuse, as you can then whittle it down a little at a time.

Always keep in mind that surfboard shaping is a “reductive process” meaning you are taking away from what is originally there.  I once had a guy ask if I could make the rails “fuller” after cutting rail bands into the blank. So I picked up the foam off the floor and put it back on the rail to illustrate my point.  When it’s gone, it’s gone, so avoid big deep acute angle cuts into your blank until you really know what you’re doing.

A good sanding block will be your best friend. Even more so than a surform. Sanding blocks are wider and more stable and will help you “true” the rail(as well as deck and bottom) as you work in long sweeping moves.  Experienced shapers can remove foam and ‘drop’ an area like the nose or tail for more rocker then come back and blend the area into a smooth flowing curve.  It’s like connecting dots A to B. 

For rail consistency from one rail to the other you can buy a 'contour caliper" for cheap at Harbor Freight. This tool holds a series of spines that you can slide back and forth that will show you the contour of your rail.  I’ve considered doing something like that where I could actually put it on a slide bar that would use the bottom of the blank as a guide, then push a predetermined rail shape like a cookie cutter into the rail making a cut indentation that I could quickly plane down to.  I use this ‘punch method’ for cutting in vee bottoms all the time. It saves me time measuring or bothering with counting bands or cuts I’m taking. 

The cookie cutter idea is limited in its approach however when you realize that you are shaping a composition of “compound curves” into a blank that changes from blank to blank depending upon what you want.  It’s the challenge of composing a symphony of compound curves that sings as a surfboard once out in the water that keeps most of us career shapers addicted for life.

Most important of all, enjoy the ride in getting to where you wanna go with it. Don’t get in a hurry, and have fun!

 

P.S. Not checked for typos, but yu get the point.

[johnmellor]

Great info right there.  Wideawake and Deadshaper hit on many important points.  

I’ve heard of guys who have a board they like wrapping coarse sandpaper (grit side out) around the rail in several places and scrubbing with blocks of foam until they have a rail impression in each block.  The blocks are then used as feeler gauges to check rail contour.  I’ve been in shaping rooms with a row of contour blocks on the shelf.

If there is one area that you want to be particularly careful when rail shaping, it is the ‘mid zone’…  Lots of boards end up with thinner rails than intended as the shaper chases mistakes in there.  There’s supposed to be taper in the ends but if you gouge that mid zone… the entire rail gets taken down to get rid of the boo boo.  

I’d also recommend not tapering the rail foil too much until you’re aft of the standing zone.  A little bulk left in the rail will keep your board from sinking too much on edge which can cause a variety of handling issues, notably tracking.  Unless you’re a dedicated hull kind of guy and like to sink those rails, a little extra buoyancy can be your friend.  That zone in aft section where the rails taper from full/buoyant to thin plays a big role in how you ‘adjust’ how much outline is in the wave.  Too thin too far forward and it’s easy to over bury your rail.

 

 

 

[DEADSHAPER]

John has points well taken.

It can be tricky to control the actual contour and volume of your rail while creating the foil you want in a surfboard.  

 

Years ago, Lauren Yater asked me how I do the full rails as he kept over tapering his rails from what he intended to come out with.  I explained the “obtuse” concept and how once he cut too deep a sharp angle deck rail band, he was doomed from the get go.   

It’s better to get the rail turned first with a lot of volume, then go back and taper it more after the fact. A lot of the pro shapers know that deep cut they can take along the deck rail to save time, but for a novice that can spell disaster.  

Although I have models that are milled that are scaled in many sizes and closer to the finish shape, i still do a LOT of hand shaping on ‘raw’ (unmilled) blanks, and even on the machined/milled ones. 

Shaping a lot of the machined blanks has led me to power sanding foam more than ever. I use two to three different variable speed disc sanders ranging from a medium pad to a super softy for wrapping rails. This is an advanced technique that the first shaper I ever heard of mowing  a few critical rail bands, then weighting the blank and swiping a super soft pad to finish the rails was Phil Becker.  He was doing 15 to 20 boards per day using this method. 

Bottom line is just to practice shaping your rails.  Even practice shaping some from scrap pieces of foam until you get the kind of rail shapes you really want on your board. Develop a disciplined technique that is comfortable to you and stick with it.  Surfboard shaping is a discipline, and when you do something that achieves a successful result, embrace that and keep it in your arsenal of talent.

[WideAWAKE]

As Bruce stated, it’s definitely a discipline. 

As much as we can understand in theory and on paper, we also must do. 

Practice, practice, practice. Each will get better than the next. 

Also, another trick Ive seen done (done myself a few times too) when making a rail or copying one you can use a coat hanger/ light wire/ solder.

you can draw out your rail, and then bend the wire to make a template or you can get an existing board and wrap the wire around the rail and you have an instant gage/template.

 

 

[petec]

The key to cutting those first bands is the dark line you can see in Mark’s pix (side light shadow).  If you were to take the width of that line and divide it by 2, it would be the rail apex (for a specific type of rail).  The rail marking dots are the edge of the lines at mid-length and 12" at nose and tail (top and bottom, apex is not marked).  The corresponding dots on the deck/ bottom will vary with the thickness and deck dome.  Those deck/bottom dots have to do with the width of the planer cut also.   Typically, the width of that dark line would be about 1/8" on the rail and will move with the rocker and rail style you’re using.  What’s so important about that thin dark line?  Well if you cut into it the outline is gone. So on those first bands (bottom first) you want to be as close to that rail dot as possible.  A trick is to use a 45 degree Fred-tool first to knock off the corner of the outline cut (1/4" x 1/4" chamfer); I’ve even seen a router used for that.  Second trick is to set the blank on edge such that the planer is level; you then cut those first bands by holding the planer sideways.  The rationale for that is you can clearly see the rail dot and where the cutter is.  In any case, you need on-the-fly adjustment to do it this way.  It can be done at fixed depth (about 1/32") or with a surform, but you’re scrubbing the rail by going back and forth rather than full passes over the length which requires too much truing of the curve in my opinion.  Once those first bands are cut, the blank is laid flat and consecutive bands are cut. When all bands are done and smooth, the corners of that dark line are finally rounded with paper/screen/dragon skin/etc. Most pro’s only use the dots at mid length and at the bottom where a hard edge ends.  The main point to remember on consecutive rail bands is that you use the edges of the planer cuts to match symetry, and that you are always cutting the top off a facet.  When the planer is cutting in this manner, increasing the cut depth increases the width of the cut and so does rotating the planer.  Rotating toward vertical makes a very narrow cut and this is done at nose/tail in lieu of decreasing cut depth (which at that point would be 1/64 - 1/32" anyway).  Some shapers feel there’s more control this way and easier to stop at the stringer.

A complicated subject to teach and describe, but Mark’s pix really tell the story.  A good way to practice with the depth control is to walk the length of the board adjusting depth but with the planer off. At mid-board the depth should be max,  so from a hard-edge tail to there you would go zero-max then max to zero towards the nose.