dr_innovation

Thanks for the positive feedback. Not positive its Red elm (also called slippery elm) but that is what the person owned the trees said -- and they got to see the leaves/buds which helps in identification. The bark and wood coloring is consistent with red elm --which is different from American or Dutch elm. Any feedback on if I should I try to glue/fill the cracks now or wait and hope the close up first? I don't want to put in wedges that cause more stress later.

Following up on cracking. I left the turtle in the garage as we took a 2-week vacation. Came back to massive new cracks. one is more than an inch wide.. and 12 in long (2.5cm x 30cm) .. the other is 1/2inx6in( 1.25cmx15cm) -- see pick below. Does one fix these as soon as they are able to (e.g. to stop the crack spreading) or do you let it keep going and then patch a larger one later? Since it can take a long time to dry if I am waiting do I keep it indoors and for how long? I've read multiple thread and other blogs on how to (and did some before I carved) but none of them said when to do it after carving.

Other than finish, here are more of the build progress threads. Note this is a hawksbill turtle (not a green sea turtle) which has a "hawk" like bill and more ornate shell pattern. I used the sapwood which was almost white to do ehe bill and some white edging on the flippers. Again this is my first carve (of any kind) and I'm pretty happy with the learning process and my wife likes the (near) final results. Thanks for the many useful threads here (and other places) and the feedback. Unfortunately it continued cracking and while the pins held during the build I had to do surgery on a flipper (though both flippers have two point of attachments so they will not just fall off even if it cracks through. Howver, the surface has lots of microcracks and many deeper edge cracks from top to bottom, . So it may not last long outside. For those that are interested, based on reading and the desire for the shell patterns, I used 3 types of stain tea followed by Vinger/iron for "black", a water-based brown transparent and a gray water-based semi-opaque for the light lines. I knew from test pieces the wood would darken a lot and I wanted the highlights on the shell, on the flippers and face to stand out. (On pic has flippers where I tried to stand patterns but was not happy with them).

Nearly finished but it still need another finish. This will be outdoors. Video below shows how fast the 3rd coat soaked in. not sure pure oil finish will work for this, the oil is just being soaked up as the surface is so cracked it just disappars even after 3 coats. of https://www.homedepot.com/p/Preserva-Wood-1-qt-Oil-Based-Clear-Penetrating-Exterior-Stain-and-Sealer-42501/100154346. Do I need to do spar urethane or something like Poly+expoxy? 20220613_175942.mp4

Thanks.. will look at that next time. For this I ended up using a "carbine cup" grinder head to and then a sanding.

Thanks for the feedback. I guess the shell could use a bit more rounding and I did originally plan for more but was getting tired. However I did not really start on the head (and feet) except the rough cutting. I was leaving head/feet for last since I know the circular saw, sanding and Dremel can get most of that done so if I run out of gas again I can still finish. My arms/hands were quite tired and so I did not want to tackle something that needed precision, like the head, and decided to start sanding to see how it looked. In doing so I learned I have to be much more careful when carving with the saw, specially when "smoothing". As it was, there are multiple gouges here and there on the shell from slight slips/digs when carving the dome shape (visible on pic with sander on it) and visible by the feet and especially on the fins.

Follow up post (progress) on the how this has held up during carving. Overall the majority of carving is done and only minimal spread. 😀 On the top, the crack had not seem to progressed at all. However on the bottom, where it was larger, it expanded a bit and develope a bit of cup cracking maybe because it could not progress linearly and so went along the ring to reduce the stress. I'll probably add more dowels on bottom.

Day two progress (about 6 hours). Finish rough chainsaw work on top, work on bottom, edged fins, refined top and fins (with cut through). Added hawksbill shell pattern. I used a circular saw for some of the surface work while chainsaw cooled (chainsaw was not starting, and waited and cleaned sparkplug and then continued). I found the circular saw more controllable for the scutes on the carapace (i.e. shell pattern). I then used a drill with carbide bit from Dremel to thicken and smooth the groves. Started sanding, still more to go but had enough for the day. Bottom will need more work.

In my first post/request for help on the log for my turtle, it was suggest I show progress. So here are some pics.. The end is about 4 hours in (ran out of gas but I only had a pint on hand). I think my turtle is starting to find their identity but has a long way to go. This red elm is pretty tough stuff so slow going; My little Dremel carbide bits were very slow on this. I am think of getting some rotary Rasps for my drill to help on smoothing and detail. This is my first carve so feedback if you think I am doing something wrong or that a rasp set would be a waste on such hardwood and I should stick to just using the chainsaw.

Well that would be nice but, I don't have a 36" drill bit and don't know anyone who does, so that was not an option. The biggest bit I have access to is 12" long bit at 1/2" diam so if I see any issues with the crack growing maybe I'll use that and larger dowels at an even shallower angle than what I did above. I will be adding wedges/glue to large section of crack after I carve and let it dry a little, so I view the smaller dowels as a temporary fix. The diagonal use of the dowel was what was not obvious to me so even though I misunderstood you thanks for the idea. And this was doable with standard tools. The dowels are is well across the crack so to expand the crack will need to fracture the dowel. Different angles provide different directional support against the fracture.

New to the forum and bumping an old thread, but just had to to say its an amazing turtle. So much nicer than the ones I've seen on youtube -- which inspired me to try my hand at carving. Now I have a real inspirational model. And I may riff-off the sponges below to use as a mounting.

Sure. Not sure of the etiquette here .. some of the boat forums I frequent do build threads, with pic/feedback along the way, My reading here seem to be finding mostly just finished piece pics.. But since you asked for progress pics, I can post regularly along the carve. If that is appropriate I'll do a separate thread on it. But since this had a question and explicit suggestion. I'll post a pic here on that and then comment how it seems during/after carving. Here is Step 1: securing the ends of the crack with dowels. My primary goal was, to stop the crack spreading while I carve. I decided to use many smaller dowels (3" each, .2" diameter, 6 dowels per side, so 12 total. I drilled them mounted at different angles just before, at, and just beyond the visible end of the crack to "sew" it up and keep it from propagating . I left the bigger section of the crack as it was -- I will deal with that after carving and a bit more drying. I ended up using bamboo rather than oak since bamboo has better compressive/tensile strength and I had them handy in the form of chopsticks 😉 The image shows one dowl after driving in and gluing and 5 in their holes. I drilled about 3.25" so I could counter sink them a little bit.

Thanks.. I should have though of that I guess I was stuck thinking in 2d. Definitely simpler to drill and dowl than do than a bowtie inlay, and I have the 3D thickness to get a good angles on them. And a few small ellipses on the shell will be pretty easy to hide.

Newbie here getting ready for a project to carve a turtle, looking for some advice.. . My goal with this piece is a chain-saw carved life-sized 3D green-see turtle to be positioned on a large rock in the yard. I've been waiting for an appropriate piece of wood since I wanted it life size its been hard to find. I recently got (for free) a sufficiently large piece of red elm. (photo below). It is green (2month from tree uprooting in wind) round slab about 37" long by 30" wide and varies in thickness from 8 to 6 inches. From reading I've been looking for a half-log but since this came along I wanted to try. My concern is that there is a crack at the core and I'm curious if I should try stabilize it before I carve or deal with the crack after carving. The heartwood is more than 2ft across and nearly 3ft long so just right for the turtle. The longest crack is about 5" radially (maybe 10" from end of crack to end) and goes through the full piece. The crack is vertical in the image. There are 2-3 smaller (maybe 1" radially) small cracks as well -- the other visible radial elements are just edges from cutting casting shadows. There is at least 7" ring of solid heartwood with no visible cracks around the outside edge. I don't mind the cracks in the surface, I'll work that into the "shell" design, but am worried that while carving or after a short while it will break apart into two pieces. I know wood continues to crack as it dries but lack experience with this type of piece. This is 6-8" thick and almost all end-grain. I just don't know how much more it will crack radially over time and hence the risk there is in carving this into nice piece -- would I be wasting my time-energy on a doomed effort. Even worse would be it breaking while carving or carving makeing it much worse. I wanted to carve it in the next week or so (for anniversary gift) , not waiting years for it to cure. If it matters the final piece would be outside -- I was originally planning on a burn+oil finish but could use epoxy if that would help keep it together and could do epoxy before or after carving. Epoxy is strong and I've seen it use in many slab tables, but it would in the crack not be across the joint, so not clear it would stop it from spreading or add strength. With epoxy I add saw dust to help it match in color. I could also try to address the carack without wood joints or metal joints . if its likely to crack apart while carving, I could chisel out and glue in some bowtie/butterfly type inserts in a few places (which again I can work into "shell design" and let that dry before I carve it). Adding it before will be much more complex. If its likely to be okay while carving, I can also add a bowtie or metal joint fastners, afterwards. But adding a bow or joint fastner tie it will not look as nice so I'd rather not do that if I can avoid it. So the questions 1) what is the risk this breaks in two while I'm carving 2) what is the risk carving without addressing crack makes the crack much worse 3) what is the risk after carving it breaks in two 4) if the risk are high, do I patch with epoxy to match or with some joint fastner? Would a 5/8" corregated metal fastner be enough (used it bottom of in tables that cracked over time) or do I need a bowtie.