I don't know how much you have, but my dh is repairing punky old window trim (major checks, and some soft spots) with Abatron products. It is labor intensive, but he is doing it himself, but he says it is a lot less work than replacing the window trim. He used it on the sills of our cellar windows. Its amazing. Plus sandable and paintable.

I could ask him to supply more details if you have a specific question I could ask him.

sorry I don't know anything about hardiplank.

Kathy

Here is a link that might be useful: Abatron

Abatron is a great product for smaller repairs and intricate shapes. It would not be something to use to repair generally deteriorated siding. I have had Hardi-plank siding on my house in the rainy Pacific NW for 10 years. It shows no signs of deterioration (and you shouldn't expect that to happen with a cement board). If you want to use it to replace your old siding, that will be a permanent fix. You could save a lot of money if you did it yourself. The only tricky part is making cuts since it is very hard: you either need to score it and snap it (an acquired skill), or use carbide blades in your saw and/or grinder and expect a lot of dust that you don't want to breathe.

I have used Abatron for years; it's great! I use the Liquid Wood epoxy, but not the white wood filler (Woodepox, IIRC), which is expensive, and feather weight, which tells me there is not much substance to it. Instead, I use sawdust and mix in enough of the Liquid Wood epoxy to form a thick paste, and apply it like putty. When it hardens, it can be sanded, sawed and will take screws and hold paint, and looks very much like the wood it replaced. For extra fine work like interior trim, I use sanding dust instead of sawdust; often it is impossible to tell where the repair was made. The local millworks were glad to give me all the sawdust I wanted for the trouble of sweeping it up since it saved them having to clean it up. For sanding dust, I have used what I was able to collect from my orbital sander.

Some of the exterior repairs I made with the epoxy/sawdust combination have been exposed to the elements for about 5 years now, and so far I see no signs of peeling paint, or cracks developing between the original wood and the epoxy/sawdust filler. I used another brand of epoxy about 20 years ago to repair a rotted window sill and it likewise shows no signs of deterioration.

Warning: do not allow Liquid Wood to contact your skin. The first couple of years I used it, I was careless about using protective gloves, got it all over my hands, and just washed it off afterwards. Then one spring I got a severe case of poison ivy rash, and ever since, contact with Liquid Wood produces a rash similar to that of poison ivy. I read some articles about sensitivity to epoxy, which indicated that prolonged or frequent exposure will generate sensitivity resulting in an allergic reaction. I suspect the poison ivy triggered the reaction, but if I had carefully followed the recommended precautions I probably wouldn't be sensitive to it. Even with protective gloves I still sometimes get a reaction resulting in a severe rash all over my fingers.

Regarding the Hardi Plank, if the original vertical trim is still in good shape I would recommend keeping it and just replacing the horizontal siding with the Hardi Plank. The siding is warranted for 50 years, but the trim boards are warranted only for something like 10 years. I had the addition to another building re-sided with Hardi several years ago. The vertical trim is very fragile and brittle, and has little strength. I saved some left over and stored it in a damp crawl space, and it disintegrates with moisture. I was able to attach a storm door to the vertical trim by drilling 1/4" holes, filling them with epoxy, and installing the screws in the epoxy (pre-drilling the screw holes). The Hardi trim would not hold screws.

Another warning: do not use a regular high speed steel drill bit to bore holes into Hardi Plank. It will quickly wear off the edge of the drill bit and ruin it, unless you are skilful and patient enough to properly re-sharpen drill bits.

donk4kyv... Not to highjack this thread, but I just posted on your thread about rotted siding; unfortunately, I didn't have a source for antique siding but provided information about an epoxy product names CPES that I've used successfully. I didn't realize you had tried other products when I posted. I hope you have success with your restoration.

hardiplank is a supperior product. If your lapboards are showing 4"'s, you can get 12' lengths, and rip them in 6" peices. Use the rough side on the side that does not show. The look blends in very well. The hardi is thinner than lap boards, so you will have to shim the butt joint to make them look better blended.

My house is 100 yrs old, and this is all I use for replacing side boards.