I made a bow for a friend of mine with all the bells and whistles. As some times happens, natural materials fail, in this case the bamboo cracked.
He asked if there was anything I could do to fix it. I could give it a super glueing and a wrap or I could replace the bamboo. I chose the latter so it would look like it did when I first made it, without a patch.
I took a ton of pictures so this is going to be a long thread and I don't know the outcome yet so here goes.
Here is the problem.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/crackedbboback.jpg)
The first step it to grind off most of the old bamboo on a belt sander. Hard to put a beautiful bows back on the sander.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/grindingoffthebamboo.jpg)
I like to leave a thin piece of bamboo to glue the new backing to so I won't loose bow poundage on the repair. This is about 1/16" thick. The initial crack was very shallow, I wet the surface of the bamboo to expose any cracks after a trip to the belt sander. None were visible.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/leavealittlebamboo.jpg)
Wow this is gonna be a cool thread :thumbsup:
This could get interesting Eric, I'll be following along.
I picked a nice piece of local bamboo, looks green but that is the color this bamboo dries to.
I drew a centerline on the bamboo belly.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/centerlineonbamboo.jpg)
Space the nodes evenly.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/matchingnodespacing.jpg)
Line the bow tips up with the center line and use the bow to make a pattern on the bamboo.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/drawingpatternonbamboo.jpg)
The finished pattern.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/finishedpattern.jpg)
I cut the larger pieces of bamboo off with a band saw, don't want to get too close to the line.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/cuttingitout.jpg)
I use a belt sander to carefully sand to my lines. I leave a little extra that I will have to sand off after the glue-up is complete.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/grindingbamboototheline-1.jpg)
Next I carefully thin and taper the bamboo on my belt sander. I have found if you make every edge 1/16" thick, stem to stern on your bamboo, it will be just right. I often see bamboo backed bows with bamboo that is much too thick
The picture is of the thinned tip of the slat.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/thinnedbambootip.jpg)
Very interesting so far. I will be staying tuned. I love to see how other , more experienced people work.
Was that the upper limb that failed Eric? Of all the boo backs that I've had fail, it was always the upper or top part of the boo (upper limb). Never the lower or trunk end of the boo (lower limb)....Art
Time for the glue-up. I didn't take pictures of me buttering up the bamboo with Urac-185 because I always get more glue on me than the bamboo and didn't want it on my camera.
I prepped the bamboo and bows back with a toothing plane iron.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/toothingbamboo.jpg)
I lined up the center line on my bamboo with the bows tips and applied my clamps. I was careful to see than nothing shifted and I had a little overlapping bamboo on each side. I glued in a little over 3" of reflex.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/glueup.jpg)
It was cool in the shop so I put my yard sale comforter/tent over my glue-up with a drop light for heat to cure the Urac.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/underthetent.jpg)
Looks pretty good out of the clamps.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/outoftheclamps.jpg)
Initial edge clean up with my belt sander. Had to be careful and not get into the bow.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/sandingoffgluebuggers.jpg)
Finished the cleanup with my file. You can see the thin strip of old bamboo I left.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/raspingtoacleanedge.jpg)
Tip overlay time. I ground off the tip overlays while prepping for the bamboo.
Measuring for a new overlay, I like 2 1/4" overlays.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/measuringforanewoverlay.jpg)
I have selected a new piece of osage burl for the overlay. I have also flattened the bow tip and bamboo for the new overlay. I cut the surface at an angle toward the bows belly so my overlay will blend into the bows back and not be a huge lump on the back of my bow.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/newpieceofburl.jpg)
Glue-up time. I use a Popsicle stick for a clamp pad as it will conform to the round belly shape and not let the clamps slip.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/gluingtip.jpg)
Turned a block of wood into a tip overlay, needs a little more sanding.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/sandingtheoverlay.jpg)
Good stuff Eric, watching with interest.
Eric,
Looking good! :thumbsup:
Very nice as usual Eric, I have done the same thing, however I only sanded the boo off the one limb. Then I had a piece of boo here that was split on one end. So I cut off the good end, laid out my bow pattern on it and glued her back up, worked out great.
Here she is, the top limb on the right is the one I replaced the boo on.
(http://i47.photobucket.com/albums/f165/ROY-CHRIS/IMG_6317.jpg)
Because round handle bows want to roll on a tillering tree I made a Vee block to cradle the handle. Still a little touchy but much better than before.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/antirollblock.jpg)
First pull on the long string, not too bad but a little stiff from mid limb out.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/firstpull.jpg)
First check with the gizmo.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/firstgizmocheck.jpg)
Yep, stiff from mid limb out.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/firstgizmoline.jpg)
That's it for today, time to take a break and start tillering in the morning
How do you spell the whistle sound you make at a hot chick walking down the street :)
Very pretty.
That comforter and light is the best-cheapest hot box yet. I am going to "build" one myself Eric. Plus, it doesnt take up shop space. Good one! Nice repair as well.
That popsicle trick on the tip overlays is pretty slick, I'm going to chalk that one up to memory.
Nice job Eric.
Thanks for documenting this process. I have a Boo-massaranduba bow that raised a nasty splinter...of course after all the work was done finishing it! It'll be a little trickier with the d/r profile, but it should work. Thanks again.
~John
Finished the tillering on the long string. With the gizmo the length of the marks get shorter and shorter until they disappear. No marks on the bottom limb and only a short mark on the top limb.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/lastlongstinggizmomark.jpg)
When the gizmo makes no marks on the either limb accept at the tips it is time to go to the short string. I left the tips a little stiff because the short string puts more tension in that area.
As you can see in the picture the bottom limb(left) is a little stiff. The poundage is 60#@22", I am shooting for 64#@31". That little strip of bamboo I left and the glued in reflex really boosted the poundage.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/firstshortstring.jpg)
I should be shooting this bow at my 25" draw this afternoon, more pictures to follow.
man..the level of talent on the Bowyers Bench..Eric..that is awesome
Like open heart surgery for a bow!
A little more progress. The short string stresses the limbs differently than the long string so a check with my gizmo reveled a few more stiff spots.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/shortstringgizmomark.jpg)
A little scraping and I was ready for full brace height. The bow is 65#@25" so I gave it a test run and shot about 50 arrows with it. Not bad but I still have to get rid of a lot of poundage. That is the good thing about using a tillering gizmo, your wood removal is so precise you end up over poundage most of the time.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/fullbrace.jpg)
I like to do my final tillering with a cheap $13 palm sander. It goes slow with 120 grit paper and takes out all the washboard effect belly scraping causes. This sander takes 1/4 sheet clamp on pads which are a pain to put on this cheap sander so I use 1/4 sheet stick on pads. When I want to change out the pad I heat it with my heat gun and it peels off easily.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/palmsander.jpg)
Probably putting the cart before the horse but I did a little dye testing on the bamboo. I have always removed the rind in the past which may be the cause of this failure. I might have nicked the bamboo and not known it.
This time I am leaving the rind intact so I tested the best way to have it take stain. My BBOs have a distinctive dye pattern and I like to keep making them look like I have in the past.
The middle test has had the bamboo rind very lightly sanded and buffed with a scotch bright pad before being dyed with Feibings med brown. The one one the right has just been buffed with a scotch bright pad, didn't take stain well. The one on the left has had the same treatment as the middle one but I used a different brand of brown leather dye which always turns green on bamboo. I tested it to see what color it would turn on the rind, green as usual.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/dyetest.jpg)
Got a request for a picture of my vise clamp pads. Pretty simple, easy to remove and offers the best protection of any vise pad I have used so far. The leather is glued on the front with Barge cement and glued and tacked on the top.
(http://img.photobucket.com/albums/v181/ekrewson/visepads.jpg)
Nice work Eric. That center test spot looks pretty good. I can see the whole back looking that way and I like it! The strung proflie is very sharp! Cant wait to see full draw pics on the tree.
Awesome craftmanship as usual!!!
Good idea for vice pads. I have some soft plastic ones with magnets, the mag's don't hold any more and it is frustrating to have them fall off often. I'm going to make a set like yours. Looks like softwood blocks?
I use blocks like Eric's, made them out of out of Poplar, very soft wood and doesn't hurt a thing. Use two gum bands to hold the blocks tight to the jaws of the vice. Eric always does nice work.
Shaun, I like 3/4" plywood the best for pads but a friend was admiring my pads in the shop one day so I gave him the plywood ones and made these out of a poplar board I had in the corner.
I never broken the plywood ones but have broken the poplar ones legs a couple of times while I was really putting the pressure on straightening a stave. I glue them back together and keep using them. You can see one glue repair behind the ruler in the picture.
So is the repair along completed or is there more to come?
Thanks Eric. This very interesting to me. I have done the same thing way back, but not nearly as professional as you. Excellent post.
Thanks for sharing, you made it look easy.
Lots more to go on the repair but I may not get to do much more for a few days.
Today I am unloading all my hunting gear from my truck that I started accumulating last September as well as getting the camper ready to pull to the Prespring Arrow Fling at Tannehill park on Friday.
Whooo Hoooo!!!! See you there!!
:coffee:
Here we go again, back from the spring fling.
The bow was 15# too heavy so I scraped and checked with my gizmo all morning, hit the desired 62#@30" just right.
Here is 15# worth of shavings.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/15lbsofshavings.jpg)
After I was satisfied with the bows poundage I began the finish process.
The first step was to sand the rind lightly.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/firstrindsanding.jpg)
I sanded the nocks with a piece of sand paper wrapped around my chainsaw file.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/chainsawfilewrappedwithsandpapaer.jpg)
I like my bamboo edges and the back to be the same color so I put a coat of tru-oil on the sides of the bamboo so the open grain wouldn't absorb more stain than the back.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/treuoiledgeing.jpg)
I stained the back with leather dye, hated the way it came out, way too streaky.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/streakystain.jpg)
Sanded it off a good bit deeper through the rind than the first time, just a little bit of rind left.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/secondrindsanding.jpg)
Looking good Eric, very nice.
I started re-staining the limbs. I use this leather dye.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/leatherdye.jpg)
I like to put it on in layers quickly so I make a swipe with my dye soaked rag and follow up with my heat gun to dry the stain quickly for the next pass.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/heatgundrying.jpg)
I like the final result which I will fade out between the nodes to achieve my "signature" dye job. The new stain is on the left, old streaky one on the right.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/newandoldstain.jpg)
Walt said he had been coating the backs of his bamboo backed bows with super glue in hopes of keeping splinters from popping up. Sounds like a good plan so I did the same, wiped it on with a small piece of rag. I really soaked the nodes with glue as well.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/superglueback.jpg)
Very interesting, great work!
Thanks for posting! Good for rooks like me to see how its done.
Great repair along Eric.
I am wondering about the super glue, could you use a finish like the one where you mix two ton epoxy and acetone or would the mixture not be strong enough to accomplish the same thing.
One of my favorite definitions of humility is "Remaining teachable". I think taking to time to share such information with the bowyer community has got to be right in there too. Thanks for the valuable information. Especially the visual reminder of how little wood is shaved to reduce fifteen pounds of draw. I am about to do a weight reduction on an old selfbow and this is timely.
Eric is definetly one of the "sages" of bowyering.
This is the "watching paint dry" segment. I have about 6 thin coats of Tru-Oil on the bow now.
I will be lettering the bow this afternoon with more pics.
Eric, that's quite a repair job, well done! I'm new at making bows and have a tough time with tillering. Can you explain a little more about the 'gizmo'?
Gizmo stuff.
http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=001047#000000
Eric, why did you remove more rine?
I had a failure onece, and decided next boo bow, not to remove it anymore. was it due to the streaking?
I didn't take all the rind off but I didn't like the dye job when I left the rind intact so I sanded off most of it but not all the way into the power fibers.
Time to letter the bow. I have used all kinds of markers in the past, sharpies and paint pens but found a better way several years ago.
I use acrylic calligraphy ink and a very fine tip pen now. This type of inks advantage is you can wipe off your lettering with a wet paper towel if you goof up and I goof up a lot. Lettering is one of my weakest skills. Here is what I use.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/inkandpen.jpg)
The smoother you get your surface the better this ink goes on. It is still a problem to put on because the pen will tend to bounce over any unfilled grains and leave a blob. I dip the pen about halfway in the ink and get the ink flowing on a piece of cardboard. I like fine lines so I expend most of the ink in the pen on the cardboard then start my lettering.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/inkoncardboard.jpg)
I have a really cheap pen, sometimes the ink won't flow so I press the tip on the limb until I get a tiny dot of ink on the limb then start writing.
The surface of this bow limb was very rough and difficult to letter, should have sanded it more before I put the finish on. I wiped off my lettering at least a dozen times, at first the whole inscription and later the last line applied that I didn't like. I guess I worked out too hard at the gym this morning and my hands were too shaky. Here is the final result.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/finishedlettering.jpg)
I like white ink on osage because it really stands out as the osage darkens. I will put three coats of Tru-Oil over the lettering after it dries to "lock" it in place, it will never come off or smear.
My ink was a little watery. I shook it up but in hindsight I should have stired it a bit to get the pigment mixed better.
Handle leather is next.
Very cool work on the boo. I love the dying job that you do. Gotta make one of your famous gizmos. How do they work on R/D or just longbows
While I had my white ink out I checked the spine and weight of some of my unmarked arrows. Seeing as how I have enough arrows to arm a medieval army, I like to know at a glance what each weighs and spines. When I shoot a tournament there is always one arrow that flies a little better than the others. This way I can identify that arrow. I put a couple coats of tru-oil over the lettering.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/arrowlettering.jpg)
Handle time.
I start with leather and barge cement. Thanks a bunch to DCM for the leather, best I have ever used.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/bargeandleather.jpg)
Half hour later, finished.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/finishedhandleleather.jpg)
Rather than rehash my stichless leather application technique, here is a how to.
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=2;t=000052
No one likes a shiny bow so I give the bow a coat of satin spar urethane to dull the shine of the tru-oil. I have found that barge cement is compatible with tru-oil but dissolves spar urethane. For this reason, to bond my leather tightly on the handle I put the leather on over the tru-oil, tape the handle and spray on the spar.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/sparandtapedbow.jpg)
I will check my spar coverage tomorrow, if it doesn't need another coat the repair will be done.
Of course I will post the obligatory full draw pic when my photographer gets back from a camping weekend with her kids.
Time to wrap it up. Here is my finished bamboo stain job, I like it.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/finishedbowstain.jpg)
I put a stringing groove in the top overlay of all my bows now, sure makes stringing easy, even for high poundage bows like this one.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/stringinggroove.jpg)
An finally the gizmo tillered full draw picture.
(http://img.photobucket.com/albums/v181/ekrewson/Chads%20bow%20repair/fulldraw.jpg)
Thats all folk.
Ahhhhhhhhhh yes, the almighty money shot! Good work Eric
That was really cool Eric. Thanks.
Jack
Real nice Eric.
Beautiful bow. I'm doing the final sanding on a bamboo-backed maple bow now. Hope it comes out half as well as this one did.
Just curious... Have you used "normal" wood stain on bamboo before? How were the results? What made you prefer the leather dye?
Leather dye penetrates better than oil based dyes and allows me to build it up to the degree I want for my bows.
You can use any kind of stain but I like the alcohol based leather dye the best. I have done test strips with just about every stain, the others were OK but not what I was looking for.
Nice Eric! Thanks for sharing the process.
It is really cool that you have a picture of Howard Hill on the back of your shirt in practicly the same pose.
Fantastic "How-To" Eric!! :readit:
Awsome Job, As Per Usual Mr. Krewson!! :notworthy: :notworthy: :goldtooth:
I was finally able to go pick up my bow today. It's only 1.5 hrs, but might as well be 1,000 miles sometimes.....
She's beautiful--I dare say it looks better, and shoots better, than she did originally. I never thought a wood bow could compare to a laminated bow for speed, smooth draw, etc. but Eric's shoot with about any, and better than most. It really does shoot as good as it looks, and pictures don't do it justice.
Thanks a million Eric!
Awesome! Eric's skill is a level above most for sure.
Holy craftsmanship batman! Great tutorial Mr. K.
Thanks...this I will save!
This one should stay close to the top or better yet added to the "How To" section for future referrence. I used it for my first BBO, great tutuorial.
Lots of guys using bamboo at the moment and they should really read through this BBO repair and use it just like it were a new build, it works just the same.
To the Top I say!! :thumbsup:
Nice save, Eric.
dont know how I missed this one. You are the man Eric. Praying for you still.
Jeff
Great infotainment as usual Eric! I think you deserve some sort of honorary doctorate or something.
dummp how I missed this, great stuff as usual Eric!!!
Amazing Work Eric. Beautiful Bow