Making Resin Blocks for Swallow Tails

Herb Spitzer’s tail protectors started me thinking about resin tail blocks for swallow tails. Kokua also had some good advice in this area. So I cast my first set of resin “tail blocks” recently and I am very happy with them so far. They are nearly undetectable after glassing (maroon tint) and I have yet to develop any of the small dings that seem to happen to swallowtails from normal “wear and tear”. Unfortunately, the pictures I have are way too large to post on the website so I incorporated them, along with a very detailed description of how I made and attached them, into a Word document. If anyone is interested in getting a copy of the document, feel free to send me a message through the website. I will be posting a picture of the finished board as soon as I can figure out how to make my camera take pictures that aren’t too large for the website to upload.

if you want to email me the pics at i’ll gladly post them on here for you.

Brandon - that would be really cool. I sent you an email to your gmail.com account. Thanks.

Troy

You can make some pretty cool resin blocks by casting them in clay.In other words…after the board is hotcoated cut the tail(or nose) off with a sharp saw.Now get some modeler’s clay and press the cut off in to the clay.By doing that you make a mold.Coat the inside of the clay mold with some clear paste wax and pour the resin.When the resin kicks pop it out and you have block ready to glue on with hardly any shaping or sanding.You do have to glass over the new block but it’s no biggie.You can pour layers of different colored resin if you want or maybe put a nice fat cockroach in for effect.

Hey, does anyone have any pictures of these Resin Blocks?

I like this idea…how do you attach the block on the blank? Can you do this even after you have laminated the board? I really like the colors resin idea cleanlines.

TM

still waitin’ for troy to send me those pix of his process…

I will send them on Monday - the pics are embedded in the Word doc. After reading the replies, I like the idea of cutting off the tips after hotcoating and using modeling clay. It is basically getting to the same result as my method (which is described in the Word document because I am too technologically ignorant to post the article with the pics). I will send the pics and the article to Brandon on Monday and hopefully he can post the whole shooting match online.

My method is for a board that has been glassed and hotcoated .After pulling the block from the mold I clean up the edge that goes on the board and glue with 5minute epoxy.I just hold it on with tape.After that dries I sand the block to get any wax off.THe block may be a hair smaller due to resin shrinkage in the mold.(set the mold resin off real slow when you pour.THe mold resin is Lam resin with no wax added).Next you sand the hotcoat by the block and glass over it.Make sure the glass goes a few inches on to the board.Hotcoat it and then sand the whole board as normal.You can buy other molding materials for resin but I Used the clay cause I had it laying around.I have seen resin blocks appled to blanks before glassing but it’s tricky to blend them in. RB

Hey Brandon - I am emailing the Word document to you now. Thanks for helping me post it online - I hope that you are able to reduce the pics and the text to a size that can be posted as a multi-part Article.

troy

no prob…i’ll have it up tonight. but i just got back from Clark Foam & Resin Research…and i’m hungry. where’s food!!!

[posted on behalf of T-Roy]

Herb Spitzer’s tail protectors started me thinking about resin tail blocks for swallow tails. I cast my first set recently and I am very happy with them so far. They are nearly undetectable after glassing (maroon tint) and I have yet to develop any of the small dings that seem to happen to swallowtails from normal “wear and tear”. Plus, if you go with a lighter resin tint then they look really trippy when you hold the board up to the sun because the light will shine through the resin tips and gives the appearance that they are “lit up”. See picture for finished product (before glassing)…

[posted on behalf of T-Roy]

I followed the following steps to cast and attach the resin tips:

Step 1: Shape the board completely but leave the swallow tail just a tad thicker than you want it near the tips. This will allow you to bring the foam down to the resin tips in the final step so there is a seemless transition from foam to resin.

Step 2: Carefully mark the blank where you want to cut the existing foam swallow tips. This can be tricky and it is not simply a matter of measuring and cutting. The key is to make sure that the two swallows look symmetrical once the resin tips are attached because the resin tips will highlight any assymetry if they are not at least close to the same size. The method I used was to pull 1" in from each swallow tip and draw a line across the swallow that would intersect the stringer at approximately 45 degrees the stringer (if the stringer were extended far enough off the tail allow for intersection). The picture above of the finished product should give an idea of how I did this because it is difficult to describe. In any event, the key is to draw lines that will result in swallow tips that look symmetrical, even if that means drawing your lines at, say, 1" on the right swallow and 1 1/16" on the left. You just have to eyeball it (unless your swallows are absolutely symmetrical already).

Step 3: Cut the swallow tips from the shaped blank. I used a Japanese backsaw to get a very flush cut but it doesn’t matter what you use so long as the cut is smooth. Mark each tip as right or left after you cut it to avoid confusion later.

Step 4: Prepare the tips for casting in plaster - you will need to prepare the tip so it releases from the plaster, which will have a tendancy to fill in the porous surface of the tip if you do not first prepare it. I experimented with wrapping the tips in clear “cling wrap” from the kitchen but it was difficult to get a wrinkle-free surface. Ultimately, I just covered the tips in Vasoline petroleum jelly, making sure that I rubbed it in to seal the pores of the foam. I am sure that there will be plenty of lurid comments made about this step of the process…

Step 5: Preparing mold - to construct the mold, I cut two 16 oz disposable plastic cups. To determine the depth of each cup, place the foam tips in the cup TIP DOWN and cut the cup about 1/8" just above the flat end of the tip. It is important that you don’t make the cups any deeper than this because you will have a tough time casting the tips if you do. MARK EACH CUP as left or right. Trust me - it avoids confusion. This picture shows a tip in the plaster filled cup. It gives a good view of where I cut the cup in relation to the top of the swallow tip.

Step 6: Mix plaster and pour in cups. I used simple, all purpose plaster. See picture…

…The key is that you want plaster the sets up fairly quickly (say, 10-20 minutes or so). I mix it according to the directions.

Step 7: Pour Plaster in cups. And wait several minutes until the plaster starts to set. You want the plaster to be just a little more liquid than the consistency of peanut butter before you proceed to Step 7.

Step 8: Insert the Vasoline covered tips in the plaster, TIP SIDE DOWN. Ideally, you want the flat side of the tip (i.e., the top side nearest the top of the cup) to be parallel to the workbench/table/bottom of the cup. Make sure that no plaster above the tips. You will need to do this step fairly quickly because the plaster is setting.

Step 9: Hold the tips in place while the plaster sets. This is why you waited in step 9 for the plaster to stark setting - you don’t want to sit around all day holding the tips in place. With a little creativity, you can probably devise a way to keep them in place without sitting there holding them but I found it easier to time the plaster so I only had to hold them about 3 minutes.

Step 10: Let the plaster set up for about 30 minutes. Go have a brew.

Step 11: After the plaster is set, you need to remove the foam tips from the mold without destroying the tips or the plaster mold. I found that the easiest way to do this was by digging carefully digging around the perimeter of the foam tip with a screwdriver, being very careful not to dig out too much plaster or gouge the foam tip. You want to be careful not to destroy the foam tips in case you mess up later and need to recast them. In addition, digging around the perimeter of the foam tip has the added benefit of widening the top portion of the mold, which will widen the top portion of the resin casting to give you a little extra resin to shape down so that it mates up perfectly with the blank. If you look carefully in this photo, you can see where I dug around the foam tip before popping it out of the plaster (see the “chewed up” or rough edge of the hole where the foam tip was sitting).

Step 12: Thoroughly coat the inside of the plaster mold with Vasoline. Don’t go overboard and leave globs of the stuff in the mold but make sure that the mold is thoroughly coated.

Step 13: Mix and pour your resin. I used normal laminating resin. I mixed the resin so that it set up slow – DO NOT MIX IT HOT or it is likely to crack. A fellow Swaylocker (Kokua) suggested mixing Cabosil with the resin to add strength. I think that this is a great idea but I couldn’t get ahold of any. Oh well – next time. Another suggestion that may add strength is finely chopped fiberglass cloth.

Step 14 : Let the resin set. I am impatient so I did not let it set overnight. Instead, I let it set to the point that it was solid but still warm enough to feel the heat from the chemical reaction that causes it to set. This has the added benefit of making it easier to rough sand with 50 grit in step 16.

Step 15: Pry the resin tips from the mold using the same process you used to pry out the foam tips. Do not destroy the mold in case you need to recast the resin tips. You probably won’t have to do too much digging around in the plaster because the digging you did to remove the foam tips will get you most of the way there. Mark the tips as left or right.

Step 16: Rough sand the wrinkles and other abnormalities from the cast resin tips. Also, rough sand the top/flat side of the tip where it meets up with the blank. I used 50 grit but be careful that you don’t go crazy and remove too much resin stock or you will be recasting.

Step 17: Let the tips harden up overnight and then start the process of sanding them down using a finer grit of sandpaper. I went all the way up to 150 grit to smooth out the surface of the tips but I still relied on the 50 grit to remove resin stock as necessary to make the lines flow. Another helpful hint is to use a very flat surface – I used a 10” X 10” piece of glass that I use to sharpen my block plane (thanks to an article posted on Swaylocks). The flat surface will allow you to get the bottom side of the tips perfectly flat and continue any hard line that you have on your rails from the foam into the resin tip. This process is actually much easier than it sounds – if you can shape the blank then you can definitely shape the resin tips to match up with the blank. Also, make sure that the edge where the resin tips meet the foam are perfectly flat. I used a wood sanding block to adjust the foam blank so that it was flush with the flat edge of the tip. Finally, I found that the best results were obtained by shaping the tip so that it is nice and smooth on the surface and flat on the bottom and – THIS PART IS VERY IMPORTANT à reduce the size (diameter) of the tip where it meets the foam by putting a piece of sandpaper on the flat surface (again, I used glass) and simply removing resin stock until the resin tip is just a tad smaller in diameter than the foam surface to which you are going to attach it. I did this by sanding the flat side of the resin tip (i.e., the side that will get glued to the blank – the “bottom of the cone” if it helps to think of it that way) until the diameter of the resin tip was about 1/16” smaller than the diameter of the foam where the tip will be glued. This will allow you to bring the foam down to the resin tip in the final step.

Step 18: Get the blank ready for attaching the tips. Place the blank on your stands so the deck if facing up and put a piece of 1” wide masking tape on the bottom of the blank starting about 8” from where the tips of your swallows would be (if you hadn’t cut them off) and running down the swallow towards the tip. Let the tape hang off of the blank so it is dangling down about 10”. The goal here is to have a strip of 1” wide masking tape attached to the bottom of the blank so that you can “wrap it” over to the top of the blank to hold the tip while the in place when you are attaching it to the blank. How you do it is irrelevant but this is what worked for me.

Step 19: Put each resin tip up to the blank one last time just to make sure that the lines flow perfectly from foam to resin and the surfaces are perfectly mated.

Step 20: Attach the tips with epoxy. I used 10 minute epoxy that comes in the two-part syringe. I mixed it up and painted it on the flat side of the resin tip and the foam where it meets the resin. As with the plaster, I waited several minutes until the epoxy was ready to kick and then held the tip to the foam. I then “wrapped” the dangling piece of 1” wide masking tape from the bottom of the blank, over the pointed end of the tip, and back up towards the thicker end of the swallow so that it would help hold the tip in place while the epoxy sets. Make sure that you check the lines again so the tip is perfectly mated to the foam and the lines flow from foam to resin tip. Stay there and wait until the epoxy has set – DO NOT walk away because the tip could shift. I strongly recommend doing one tip at a time.

Step 21: Let the epoxy fully harden.

Step 22: Remove the masking tape and reduce the foam swallows so that the foam mates up perfectly to the resin tip. I used a drywall screen and sandpaper (just like shaping the blank).

Step 23: Glass the board and have fun!