When to use which? The easiest way is to remember is this: 🪵 wood to wood & gouges/scratches = wood filler. 🦷 seams & gaps = caulk.
It depends on the application. Wood filler is ideal for filling holes, cracks, and joints in wood surfaces, providing a solid, paintable finish. Caulk, on the other hand, is better for sealing gaps where flexibility is required, such as in joints between trim and walls.
Wood to metal joints: Any type of wood to metal joint shouldn't be caulked because it will increase the risk of water damage.
You shouldn't use wood filler on wood that is already finished or on wood that is to be used in an exterior setting. Wood filler shrinks and hardens and will fail in the event of expansion and contraction, which is much more likely in exterior uses than interior uses.
When should I use wood filler versus caulk? Generally speaking, you should use wood filler on flat surfaces and when repairing joints between two pieces of the same material in a woodworking project. Caulk, however, should be used to fill gaps between two different materials.
You can fill gaps up to 1/8". For wider gaps, it may be more aesthetically pleasing to insert a matching wood "sliver" or "dutchman" before applying the filler. This approach provides a more seamless and natural appearance.
Wood filler tends to shrink and crack. It doesn't smooth out as well which can be visible when paint is applied. Doesn't dry very hard and can be easily dented and stay malleable with larger repairs.
Over-tightening can put too much stress on your wood filler, causing cracks or looseness. If you're using Durham's Water Putty for this project, another option would be to insert the screw into the putty while it's still wet. Allow it to dry thoroughly, ideally overnight, for a secure hold.
You can recaulk over old caulk, but you should never do it.
Our recaulking experts will remove every bit of your icky, failing caulk. Then, they will add an anti-mold treatment to eliminate mold and mildew and fight future mold and mildew growth. They will apply a 100% silicone caulk, which resists shrinking over time.
Quick answer: Don't caulk the weep holes, moving portions, or the tops of your windows.
To fill large gaps in wood, use a two-part epoxy or wood filler designed for structural repairs. These materials can be molded and sanded to match the wood surface. For aesthetic purposes, consider mixing sawdust from the same wood type with glue to create a filler that blends seamlessly.
Epoxy Wood Fillers
Epoxy fillers are fantastic for filling voids as they don't shrink over time, and they are as flexible as wood. Once dried, they can be sanded for a smooth finish, painted, and even look great underwood oils and varnishes too. For us, Epoxy wood fillers are the most versatile filler on the market.
Here are some of the best options for different types of materials: Wood: For sealing gaps in wood, a silicone caulk such as DAP 100% Silicone Window, Door and Siding Sealant is a great choice.
Wood filler repairs dents, gouges, and scratches in unfinished furniture. It is also used to fix holes in wood flooring and cover cracks in unfinished woodwork. It is best suited for non-structural repairs.
You can buy various brands of paste-like wood filler that will disguise smaller gaps. It won't take stain like wood, but a repair that runs parallel to the grain will blend in nicely. Holes call for different tactics. Putties and sticks of all kinds come in various colors and are designed to match your wood.
Yes – absolutely. Silicone caulk is effective for bonding and sealing wood surfaces. Its versatility ensures secure and durable adhesion and results in a long-lasting finish. Silicone caulk creates a flexible, robust barrier.