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Ryan,
Go to www.abatron.com and look at there structural epoxies for wood restoration. I have their literature and it shows using their products for just this scenario. I used similar materials in kayak building and they are easy to work, exceedingly strong and durable. In fact I have two kayaks built 15 years ago that have spent their whole lives in the water or under a tree.
This stuff is expensive but is cost effective in situations such as these. Basically you remove the punky wood until you hit the solid stuff, the brush or pour on a consolidant which strengthens the remaining wood and primes it for the epoxy. The object is to use as little of this stuff as possible, so you would now make a repair filling in with wood, similar to what has been described above. Fill any voids with the epoxy paste and sand and paint. Solves the problem of hiding the joint anyhow. What makes abatron’s products unique is the different viscosities of material that allow you to pour it, trowel it and mold it. The same thing could be accomplished with any two part epoxy, such as West’s system three for boatbuilding, and adding thickening agents such as cavasil (sp?) or microspheres to get it to the desired consistency and sandability.
Might be worth checking out.
Tom
Replies
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you can use bleach to kill bacteria eating the wood.use the epoxy .hopefully your only replacing 6 or 8 inches
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Ryan -- any chance of going back with soemthing other than a 6x6 base for the part you add to the post?
How about a 8x8 that has had some fancy router work and the top has been dished out so the 6x6 sits in the dish. Whatever you do the additional, 6x6 may show -- using the 8x8 it may look like part of the original.
*Ryan, The post above mentioning the Abatron products is worth checking out. Depends on how much post you actually have to replace. Their literature shows a post base being recast in place and doing a fine job of bearing weight after curing. I have used the Abatron Wood pox system for years to repair rotten window sills that would have otherwise required incredibly costly repairs if done by conventional methods. I recast the bottoms of nearly 160 turned balusters on a widow's walk on an ante bellum mansion. It is a mess to work with and not cheap per volume gained, but cheaper than the work required to replace or splice in new material. Abatron makes epoxy products to fix just about anything, I have only used the wood epoxy system though with great success each time. I have a similar repair project for a client who has a deteriorated 6x6 post with half walls attached either side, siding, trim. Problem is that the rot extends up into the post behind solid post face. I plan to seal off the bottom to prevent leakage, bore down into the rotten area at an angle from above, pour a mix of liquid and solid wood epoxy (I believe the instructions say you can intermix the two for any given consistency) into the hole until is tops out. I'll use the solid to patch the bore hole. I haven't tried to use the stuff in this way yet but do not see why it won't work. Even if you don't need it for this application, it's good material to be aware of if you get around restoration projects where existing materials are so fragile or irreplaceable that in-place repair is the only option.
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I'm repairing an old porch. The bottoms of the posts are rotten, the tops of the posts are beautifully trimed. I would like to replace only the bottom couple of feet of post. What's the best joint to splice these posts (square). I'd like a shiplap joint but don't know of a way to cut a really tight one in a 6x6 post. The best I could do is use a mortising chisel but that's a big splice to keep tight (at least fo me).
*Ryan-I think you're on the right track. A sharp handsaw (one that doesn't plug in) couple of good chisels and a plane to dress the joints out. Don't know how many posts you got but give yourself lots of time.It will get easier as you go.
*Ryan,I do these with a butt joint and a 3/4 piece of allthread, sometimes try to hide joint other times make decorative ie roundover on top and bottom. If you can't swing the top out enough you have to drill deep so the 3/4 can push up to clear bottom. KK
*It sounds like trying to work these post while they are installed could be a real challange.You could probably work them one at a time without supporting the porch roof, but I'm inclined to support it anyway.You can then make a crosscut with the sawzall to remove the rotton part. But what holds the now "hanging" existing remainder of the column? You can brace it off to the ground, but the braces will be in the way of working the new joint.It's a shame that you can't take the whole column down to render the repair on the saw horses. It would be so much quicker and easier. I'd use a scarfed shiplap joint so water would not collect in the new joinery.It's possible to do this, but it won't be easy. Lots of hand work with an unstable column just hanging there. Like the man said......allow lots of time. If you can cover a butt joint with moulding, it might be quicker. That way the joinery won't have to be perfect. I like the idea of the allthread that kkearney brought up.My advice? Take the column down, replace the whole 6x6. Do it right.Ed. Williams
*Ryan, here's an idea FWIW.Weight from above tightens the joint, the shoulders support the weight and keep the joint from splitting and a couple of plugged screws (or lags) from each side keeps the whole thing together OR you could draw pin the thing together too. What do you think. Too fancy? It is a strong joint.
*Good suggestions everyone,I vote for the simple shiplap or halflap joint, with PU glue. I will probably keep pretty dry since its off the floor. I think Ralph's joint would satisfy any nitpicking restoration guy and wouldn't be much harder. The trick is take the posts down and use the bandsaw. As a rule of thumb it should cost about 4 times installing new posts. I'd like to see a picture of this porch.Tom
*Ryan,If you're not concerned with the way the shiplap joint would look, then fine. There are a lot of ways to make this simple joint. But what if you went ultra simple, just butt join the two post pieces, and predrill 5 holes, 4 surrounding one in the center, and inserting rebar or other dowel-shaped rods into each butt? You'd have to get some clearance, or bend the posts out, or install pedestals under the new post pieces, but it may be possible. A really strong connection would use hardened lag screws on one butt, with the hex heads ground or sawed off. If you're still worried about sideways forces acting upon the posts, you could run rails between them or add some stiff lumber material as a means of bracing as a design to strengthen the joints.Shiplapping the hanging posts would be challe
*Hey Ryan-I was assuming you could prop the porch and bench the posts- I wouldn't try to make razor tight joints on them standing. An exercise in futility. Kearny's solution is most attractive in that circumstance...
*The reason for leaving the posts in place is that the tops of the posts are attached to some pretty intricate gingerbreadwork. If the stuff's original it's at least 150yrs old and has been "fixed" several times over the years. I'm sure I can't remove any of it without it falling appart.I'll certainly jack the porch, but just enough to take the weight off the posts. No chance of lifting it any more than a fraction of an inch.I like the idea of butt joints much better, of course, I'm not sure how I'll make a perfectly square cut on a 6x6 post still attached to the porch either. I can insert a piece of post that's a few inches too short and then slide in another piece that will be wrapped by a base molding. That way I can use the inserted rod idea.Thanks everybody.
*If the posts are to be painted, you could run a thin bead of painter's caulk around the perimeter of the bottom piece, then when you join them up, this would fill any small void, and you can wipe the rest off. If the voids are bigger, you could use bondo and sand it off. But I think you'll be able to get a pretty good joint. Could saw off a tad long and beltsand to a squared line, and even cheat a little by hollowing the inside i slightlyand use the beltsander to sort of scribe to fit the bottoms.I'm sure you'll get them as good as you want
*Undercutting or hollowing out the inside of the joint is an old timber framers trick. Works great.Nice tip Mad Dog.Ed. Williams
*a tight fit for appearance could be made by setting the skil to a 1 or maybe 2 degree bevel, (check this with a speed square against the table to the blade with the table set to full depth). Run the saw around the post on marks that actually end on the line where the square lines started( make sense? if the line doesn't end up on the initial line ,at the end of the fourth side, then neither will the saw.) Visualize where the bevel goes to undercut. Cut the midlle of the line, use a thin kerf blade, and pay attention to the way the line disappears as the cut is made. Follow through evenly all the way through the cut until the saw is out. Get your body down so the cut is at eye level. You can make super clean cuts with a skil if your mechanics are good. Good luck on joining them without taking them down. Any rod material will require the post to be swung out, the longer the rod, the longer the swing, and probable damage to the froo-froo at the top. I wonder what shape the deck is in under the rotted columns? Can you find a way to come up from below to drill and thread? maybe some decorative metal that wraps up the column at the splice and allows for enough through bolts to a matching piece of metal on the other side. I would want probable three bolts per column side at the splice. Wish I was there
*Yeah, the decks in good condition (as much as I can see without taking it apart) but the deck boards are gonna be replaced.
*Ryan,Go to http://www.abatron.com and look at there structural epoxies for wood restoration. I have their literature and it shows using their products for just this scenario. I used similar materials in kayak building and they are easy to work, exceedingly strong and durable. In fact I have two kayaks built 15 years ago that have spent their whole lives in the water or under a tree.This stuff is expensive but is cost effective in situations such as these. Basically you remove the punky wood until you hit the solid stuff, the brush or pour on a consolidant which strengthens the remaining wood and primes it for the epoxy. The object is to use as little of this stuff as possible, so you would now make a repair filling in with wood, similar to what has been described above. Fill any voids with the epoxy paste and sand and paint. Solves the problem of hiding the joint anyhow. What makes abatron's products unique is the different viscosities of material that allow you to pour it, trowel it and mold it. The same thing could be accomplished with any two part epoxy, such as West's system three for boatbuilding, and adding thickening agents such as cavasil (sp?) or microspheres to get it to the desired consistency and sandability.Might be worth checking out.Tom
*Hey nathan,Good trick on the undercut. The timber framers use an autobody grinder. We use a little 4" grinder to scoop out the undercut. A pencil line on the outside edge keeps you from grinding too close to the edge.Great tip with the skilsaw though. The fewer tools the better.Ed. Williams
*Kinda late here, but what the heck...First of all, I do this same job an awful lot. What I have found is that the new posts, and the old posts are not the same size, especially if you have older posts with some serious age on them (50 or 60 years or so).Next thing to consider: are you going back with PT for the bottom? If not, what are you going to do to make sure the bottom is rot proof this time around?Next thing is what to do about the size difference in the two posts. All the fancy joinery techniques will take an enormous amount of time, and you will still get a bad looking joint. In order to get a good, tight fitting joint, and a seam that is nearly invisible, you would need to completely remove the posts, and plane down either the old post, or the new one, depending on which is actually bigger.Or... What I do when faced with this situation is to get the weight off the base of the post, but just barely. I take a 1 x 2, and a torpedo level and make a nice little guide all the way around the post. I put a screw in each side to hold it tight to the post, and run my skilsaw all the way around the post, using the guide as a straight edge. I get a sqaure, flat cut all the way through.I cut a new section of post using a PT post, and squirt a generous dab of caulking all over the top, concentrating on the edges. I slip the new section in, let off just a slight amount of pressure (this gets the new post bottom fitted in) and I then adjust as necessary to get plumb and square. I then let all the weight off, and wipe off the excess cauliing that oozes out. This makes the joint watertight. Next I countersink two screw holes on each of the four sides of the old post sections, angled down to the new. I then drive in 2 1/2" Deck Mate screws, and use an exterior wood filler to fill in the holes. I do the same for the base, except I only use one screw per side.Now I cover the new joint/seam with a thin board, beveled on the top side to repel water. I make the new trim cover fit in with the other trim/decorative woodwork on the porch. I then do the same decorative trim on all of the remaining posts so that it looks even, and like it was always supposed to be like that.This is just how I do it... it is easier, much less time consuming, and always looks good.Just my opinion...James DuHamel