I have done a lot of restorations on our home. We have an old 1920's Tudor, and I've had to patch a lot of wood surfaces with imperfections. I don't know why they would use caulk on a railing, unless they are concerned about expansion and contraction. Are the areas that need to be filled where joints meet up? If it's a stationary surface, I'd use a wood putty. I've always used Dap wood filler - I purchased at Home Depot. It dries hard as a rock, can be sanded, stained, drilled, painted, etc. Extremely durable. If it's floor boards then I can see why they don't want to fill with a putty because the joints need to expand and contract with the changes in weather temperature.

The only place I can think of to use caulk is around windows or window frames.

Hey, thanks a lot for responding!

The area that the second painter was poking at is on the top railing for the steps that go from the porch down to the sidewalk. Not the floor boards (those are stained and unpainted). I don't think it was where joints met, but thanks for mentioning that--I will take another look. I think it was even the top of the railing, where the top layer of pain is peeling, and looks like it was just a gouge in the wood rail that when they painted the last time, someone filled in to even out the surface.

The porch is in the front, has the railing (top and bottom rails) plus the little posts (balustrade?) between the top and bottom rails, and the big posts holding the porch roof up. The railing goes around the front of the porch and then also on both sides of the steps going down to the sidewalk.

Would choosing to use caulk have anything to do with the moisture we'd expect the painted surfaces to get? I mean, the railings are likely to get hit with rain a lot when it rains (we're on top of a hill and the wind doth blow). Plus it is in Massachusetts and humid in the summertime.

Thanks!
LA

I have had luck with Gorilla glue and a pumice stone to fill cracks in the wood siding of my home, and painted over it and it is very unnotible even after 6 years. Way better than the caulk used previously.

I wonder if it would work as a smoother for weathered areas as you speak. It Caulk and wood putty do not seem to be real long term solutions, but sound like the only other solutions.

By all means the best solution is to use a good wood putty caulking will always be somewhat soft and not a good choice for this application. If the old paint is peeling away from the old wood putty it could be that the putty was not completely dry when it was origionaly painted which resulted in the adhesion loss over time...Good Luck...

Plain and simple caulk is for joints....between 2 pieces of wood where they meet. You can also use caulk for cracks, but not for repairs or filling nail holes. A lot of painters I see use glaze to do repairs and they call the glaze putty as a generic term. It's oil based and takes forever to dry and hardly any painter would actually wait for it to dry before painting over it. Of course it doesn't last long. Maybe that is what the painter is referring to when he says he would not use putty...just a guess. Putty that dries hard is okay to use.

I've used the Elmer's wood filler with both good and bad results on exterior surfaces - good results on nail holes and small cracks in vertical surfaces (i.e. exterior siding). Bad results on a fairly wide and deep hole on a horizontal surface (windowsill) which took a lot of filler (according to the instructions, that should have been okay). The wood filler dried hard, it had a good week or two before I painted. A couple of days after I painted it rained and the filler turned soft and expanded under the paint - I could actually dig a fingernail into it. I ended up pulling it all out - it was all damp and it cracked the paint.

I'm not sure how large your wood repair is, or if it's on a horizontal surface, but maybe Dap or something else would be a better choice.

My deck railing has become the site of hungery wood bees drilling holes and wood chips indicate wood peckers are enlarging the holes. I have used wood filler, but the little demons are back and making holes in my wood filler. What can I use that will be hard enough to fill the holes for good? Any info will be greatly appreciated.

I know this is an old post but I had to reply.

The second decorator would be classed as a cowboy builder (similar to a con artist) in the UK. Using caulk is about as bad as it gets if filling flat surfaces, for one it will sink , secondly it will not sand and if you try, it will end up peeling off. Caulk is ok for edges i.e. where skirting meets wall, ceiling meets wall, down the edges of architrave but never to fill a hole.

Wood putty is good for certain jobs and a skilled decorator can fill just about anything with it. Unfortunately in these days of "instant everything" putty takes a while to form a skin and eventually harden completely, once hardened it can be sanded but not until. One also has to be careful about the linseed oils that putty is blinded with, and if the putty separates i.e the oil settles on top, you have to make sure the putty is well mixed with the oil before application; again this can take time and can also be messy.

Use a proper wood filler with a fine finish, never try to fill a deep hole in one go, always do it in layers. Always follow the makers instructions for application, I mention this because there is always someone who seems to know better than the people who actually make the product.

Well... I'm a minority of one here... 37 years ago I started on our old house & I'm still going. I've done pretty much everything myself (yes, up to code) so I know what I've done in the past and how it's held up.

Wood filler absolutely does not last under outside paint. Period. (The book "Wood" might be a good starting point to explain why.) Basically, wood moves. Filler does not. Starting to see the problem here? I did it and after 10 years or so it started falling out.. oops.

Yes, caulk works. But you have to keep applying thin layers forever to get around the shrinkage problem. DAP used to have an elastomeric filler... it was basically thick caulk, so the shrinkage problem was still there, but not as hard to build up.

Wood glued in place is probably ideal, but it can be hard or impossible to get a piece that fits the damaged portion tightly. Use an aliphatic resin glue (yellow wood glue) - it gives a little so it can handle the wood shrinking and expanding.

You can try a thin layer of caulk for better adhesion, followed by filler immediately, while the caulk is wet. The layer of embedded caulk gives enough it may keep the filler from coming loose.

Whatever you do, you need to apply a layer of wood hardener first if the wood is weathered- ie. gray. At that point the lignin- the glue that holds the wood fibers together- is gone, so whatever you put in the hole will come loose, still attached to those weak wood fibers. Lacquer-based hardeners (Minwax) work ok; if you want it to be as strong as the original wood, use epoxy that's made for the purpose (Abatron). It's thin so it soaks into the wood nicely and leaves it stronger than the original. Then fill.

Good luck! And the guy who said wood filler would come loose... he was dead on.