joelpro Posted August 16, 2011 Report Share Posted August 16, 2011 I'm working on my first project where I'm trying to join two pieces of white oak for a table top. I spent this evening trying to rip the boards, so I could join them with some dowels, but as you can see in the picture, each side seemed to have a "bow"--meaning the ends of the boards met just fine, but in the middle there was a gap. I tried all the sides to see if any two would fit together correctly, and all of them exhibited the same behavior. Up to this point, I've used softer woods like cypress and cedar, and if that has happened, I've been able to just bend them with clamps, so they met in the middle, but the white oak is my first attempt at hardwoods. What am I doing wrong in my ripping that would create boards that come out shaped like the exaggerated diagram? Thanks for any help you can give. Quote Link to comment Share on other sites More sharing options...
rmac Posted August 16, 2011 Report Share Posted August 16, 2011 First question is, "How are you ripping them?" On a table saw, or a bandsaw, or by hand, or ??? -- Russ Quote Link to comment Share on other sites More sharing options...
mikepdarr Posted August 16, 2011 Report Share Posted August 16, 2011 You need to joint them in some way. Either with a hand plane, an electric jointer or a router with a straight edge and guide bearing. Running a bowed board on a straight table saw fence is still likely to produce a bowed board. Quote Link to comment Share on other sites More sharing options...
joelpro Posted August 16, 2011 Author Report Share Posted August 16, 2011 Thanks for the help guys. I thought after I posted that I left the key detail that I was ripping on a table saw. Thanks Mike for the router/straight edge idea. I don't have a jointer, and I've never thought of that before. I'll definitely try that as it sounds like it will work well in my shop. On a side note, I did hot glue a 3 in wide mdf board to the board being ripped to act as a straight edge on my fence. Was that a silly idea? Quote Link to comment Share on other sites More sharing options...
Sac Posted August 16, 2011 Report Share Posted August 16, 2011 That wasnt a silly idea at all.. There are jigs with a similar purpose in mind. The router and and straight edge is probably your best bet. And also check to make sure that your fence is straight and square.. Quote Link to comment Share on other sites More sharing options...
Jesse Posted August 16, 2011 Report Share Posted August 16, 2011 I built this jig to make edge joint worthy rips on my tablesaw: It rides on a runner in the miter slot, so there's no worry about left or right movement, fence alignment, etc. It can also be used to make tapers, mitered edge joints, and probably a lot of other tricky cuts. More info here: Quote Link to comment Share on other sites More sharing options...
davestanton Posted August 16, 2011 Report Share Posted August 16, 2011 Joel. I worked for a few years in a joinery shop that specialised in large timber tops and we had to join in many ways. Here is a tip when using a router and straight edge to true the joint. If both faces of the boards are flat and parallel, ie. thicknessed, then edge each board from the alternate face. In other words, Router against a straight edge from the top of the first board and then flip the next board over and router its edge from what would be the bottom. This eliminates any out of plumb that your router may have. Make sure you mark all the joints so that you remember what goes where. Quote Link to comment Share on other sites More sharing options...
joelpro Posted August 16, 2011 Author Report Share Posted August 16, 2011 Thanks everybody. Last night I dowelled and glued the boards with a gap in the middle because I thought that was the best I was going to get. You guys have inspired me. I'm cutting through that joint tonight, routing both edges (thanks for the alternate face idea), and I'm going to do this right. SavageCraft, your idea is huge for me. I have an incredibly small fence/table--it's a ShopSmith I inherited. This will allow me to rip or taper or really anything I want without the tiny table messing me up. I will be building this soon. Quote Link to comment Share on other sites More sharing options...
Rick LoDico Posted August 16, 2011 Report Share Posted August 16, 2011 There's more to joining two boards together than two straight edges. The boards also have to be flat and of equal thickness. When you have that the dowels become totally unnecessary. The ideal tools for this process are the jointer, planer and table saw. Quote Link to comment Share on other sites More sharing options...
Dan S Posted August 16, 2011 Report Share Posted August 16, 2011 Another thing to check, is if your saws fence has crook (the center of the fence is further away from the blade than the ends). If your fence has crook even if the edge of the board running along it is dead strait you will still get bow. Quote Link to comment Share on other sites More sharing options...
joelpro Posted August 16, 2011 Author Report Share Posted August 16, 2011 Thanks Rick and Dan. The boards are flat, and just recently thicknessed, so I think the problem is in my edge jointing. Would be a lot easier were I to have a jointer, but until my shop doesn't share space with my truck, I'll have to get creative. Now, to the shop! Quote Link to comment Share on other sites More sharing options...
Rick LoDico Posted August 17, 2011 Report Share Posted August 17, 2011 Here's a simple way to joint an edge: Quote Link to comment Share on other sites More sharing options...
Jesse Posted August 17, 2011 Report Share Posted August 17, 2011 SavageCraft, your idea is huge for me. I have an incredibly small fence/table--it's a ShopSmith I inherited. This will allow me to rip or taper or really anything I want without the tiny table messing me up. I will be building this soon. Yeah, I know. I'm just doing my part to make the world a better place, one clean cut at a time. Quote Link to comment Share on other sites More sharing options...
joelpro Posted August 17, 2011 Author Report Share Posted August 17, 2011 Just an update, I used a 5in wide piece of MDF and my flush trim bit to route a straight edge and the two boards joined beautifully. Thanks! Quote Link to comment Share on other sites More sharing options...
rmac Posted August 17, 2011 Report Share Posted August 17, 2011 Good! Now, can you take an edge that you've straightened with your router, place it against your table saw fence, and rip the board so that the other edge is also straight? If you can, you're in business. If you can't then something is wrong with your saw. -- Russ Quote Link to comment Share on other sites More sharing options...
joelpro Posted August 20, 2011 Author Report Share Posted August 20, 2011 Ahhh, good idea Russ, however, I might not need to do so, as when I place my straight edge against my fence as Dan suggested, it did show a bow. Not good news, but I think you guys have provided enough work arounds I can do without until I have more room for a better saw. Quote Link to comment Share on other sites More sharing options...
rmac Posted August 20, 2011 Report Share Posted August 20, 2011 Ah, so the fence is crooked! That explains a lot. Can you add some sort of auxiliary fence to the existing one that you could then shim until it was straight? -- Russ Quote Link to comment Share on other sites More sharing options...
joelpro Posted August 20, 2011 Author Report Share Posted August 20, 2011 And another great idea. Thanks. I've been toying with adding some plywood to it in order to extend it past the table thinking that would help me manage the tiny table better. That's another reason to give it a try. Now I have a new jig to build as well as auxiliary fence. The list is growing. Quote Link to comment Share on other sites More sharing options...
ronteti Posted August 22, 2011 Report Share Posted August 22, 2011 Table saw problems for the most part boil down to a few things. the fence, moving/alignment blade, sharpness/alignment arbor bearings/wearing out/ assembly out of alignment Thats about 90 of the tools issues. Quote Link to comment Share on other sites More sharing options...
LoneRider Posted September 30, 2011 Report Share Posted September 30, 2011 A bit late, but, this might help. I have a Festool saw, and also a Unisaw, but, I don't have a jointer. Placing both boards together and ripping them does not seem the safest thing to me. But placing the boards together in a similar fashion and running the Festool saw works very well. Quote Link to comment Share on other sites More sharing options...
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