One Rotted Antique Door

By Greg Bull

A friend of mine was looking to add a little character to his home. While in an antique shop, he came across an intricate door which happened to have all the features he was looking for. It was a beautiful door at one time, and worth keeping around, but needed a little TLC before painting and installing.

Four Common Repairs

Right away, I noticed five areas that needed repair. The original hardware for the doorknob and lock were missing. The voids needed repairing to install modern hardware. The top hinge plate was loose due to stripped wood around the screw threads. Part of the window ledge had been broken off and needed rebuilding. Finally, like most seasoned exterior wooden doors, this door suffered from rot deterioration along the bottom edge.

REPAIR 1: Doorknob

To begin, I removed the paint that was on the surface and any loose or deteriorated wood to see how much area I would need to fill. Once the bad wood was removed, there was a decent-sized cavity.

There are two approaches I could have taken to fill this space. One approach is to fill the cavity full of layers of epoxy. Because epoxy generates heat when it cures, you have to be careful with how deep you pour epoxy. “Deep” varies based on the epoxy system you use and the working temperature. A good rule of thumb for our 105 Epoxy Resin® and 206 Slow Hardener® combination is, at 72°F, you can pour a ¼” maximum depth every 2.5-3 hours. With the size of this hole it would take multiple pours, a lot of time, and use a lot of epoxy. The second method, which I opted for, involved filling most of the volume with a wood plug, bonded in place with thickened WEST SYSTEM Epoxy. This allowed me to fill the hole in one step, which was much more efficient use of time and materials.

I squared off the cavity, so fitting a wood plug to fill the volume would be easier. I measured the space, found a piece of scrap wood of proper thickness, then cut it roughly to shape.

To prepare for epoxying, I taped off the back side of the door with clear plastic packing tape so thickened epoxy would be contained in the door handle opening. The 105 System does not bond to plastic packing tape, which made for an easy removal.

I broke out the 105 Epoxy Resin with 205 Fast Hardener®, mixed up a batch of epoxy, coated the inside of the void in the door, then the surface of the wooden plug. This initial coat of neat (unthickened) epoxy penetrates the wood surfaces. I mixed up a second batch, adding 410 Microlight® Filler until the epoxy was between a mayonnaise and peanut butter consistency. The 410 Microlight Filler is strong enough to bond in the wood plug while still being easy to sand, so it was a perfect choice for this application.

I generously applied the thickened epoxy into the void and then coated the wooden plug before inserting it. I spread the squeeze-out, leveling it slightly proud of the surrounding door surfaces. I had to apply a little extra epoxy in a few low areas. Then, I left the epoxy to cure.

The first fill was not perfect. I sanded the epoxy flush with the height of the surrounding surfaces on the face and edge of the door. I scuffed the few remaining low spots and applied another coat of 105 / 205 / 410. Again, this was allowed to cure and sanded flush.

I flipped the door over, removed my backer tape, and sanded flush. There were a few small voids where the tape was wavy or trapped a couple air bubbles. Again, I scuffed up the low areas and reapplied thickened epoxy. After curing,
I sanded flush.

The surface now needed to be sealed. I applied two coats of 105 Epoxy Resin mixed with 205 Fast Hardener. I waited about 90 minutes between coats. The surface was ready to be prepped for paint.

REPAIR 2: Vertical Deadbolt

There was a hole that ran completely through the door and on one side, the surface had been recessed by about ¼” to mount the lock.

I started with the same approach as the doorknob. I sanded the surrounding surface and inside the hole down to bare wood. In our scrap pile, I found a dowel almost the perfect diameter to fill the lock hole. Using this as my wood plug, I trimmed it to the approximate thickness of the door.

For epoxying this part of the door, I used a hybrid approach of the two processes I considered for the doorknob area. I filled the thru hole with a wooden plug and the recessed area with a layer of thickened epoxy. Again, I applied my tape backer to help hold the plug and epoxy in place. I also applied tape to the edge of the door to prevent the epoxy from running or sagging out of the recessed area. Then it was time to mix the epoxy.

Using 105 Epoxy Resin and 205 Fast Hardener, I wet out the hole and my plug with neat epoxy. I then added 410 Microlight Filler until the mixture reached a mayonnaise/peanut butter consistency. I liberally coated the inside of the hole and the plug with the thickened mixture. I spread the squeeze out from the plug around the surrounding area to ensure the plug and epoxy were proud of the surface. After curing, I sanded it flush.

Before applying my epoxy filler coat to the recessed area, I wanted the plug to cure so I had a solid surface to push against. I wasn’t in a hurry, and this prevented the plug from moving as I worked (which could have potentially created more voids).

The recessed area was only about ¼” deep, so I was comfortable my epoxy mixture would not overheat once applied. I mixed a batch of 105 / 205 and brushed the neat epoxy onto the recessed area. Then, I thickened the rest of the batch to a mayonnaise consistency with 410 Microlight. I started at the back edge of
the recess and slowly worked my way towards the edge of the door and my tape barricade. This way I minimized the likelihood of trapping air pockets under
the thickened epoxy.

Once this cured, I sanded it flush to inspect. Some touch ups were needed to fully square off the edge and fill a couple low spots. I mixed one more batch to apply; that was subsequently sanded flush. Then, I applied a coat of neat 105 / 205 to the entire area to seal the epoxy.

REPAIR 3: Door Hinge

I removed the screw and wiped it with a clean paper towel to remove any loose rust or debris. Then, to prepare the screw for epoxy, I sprayed it with cooking spray. The spray prevents the epoxy from sticking to the screw, so you could back the screw out if you needed to later.

For this repair, I chose our G/5® Five-Minute Adhesive. G/5 cures quickly, so you must work quickly, but it has excellent adhesion to wood. I added a little 406 Colloidal Silica, thickening the mix to a peanut butter consistency so that the epoxy did not drain out of the screw hole while curing.

I applied the mixture to the threads of the screw to ensure the epoxy didn’t trap air between the grooves. Using a mixing stick, I forced the epoxy from the mix into the screw hole. Then I took my screw and ran it in and out of the hole a few times to work the epoxy down the length of the hole. Sometimes, you can get an air pocket stuck in the bottom of the hole, which helps disrupt that, allowing the epoxy to work its way to the bottom. Alternatively, I could have used a syringe to inject the epoxy from the bottom of the hole outward.

Once satisfied the hole was sufficiently coated, I applied a little more epoxy to the threads and inserted the screw back into the hole. I made sure the head was flush with the hinge plate. Then I removed the excess squeeze out, so I could back our screw out later if I wanted.

Repair 4: Door Window Ledge

Removing the ledge would be detrimental to the character of the door, so I needed to repair it. My approach was to make a splash mold on the good end of the ledge to rebuild the missing end.

I removed the paint from a section of the ledge with the least amount of damage. I covered the area where I would build my mold using clear plastic packing tape. I made the mold as big as I could in my undamaged area. I had to keep the tape smooth and tuck it tightly into all my corners to get the most accurate shape possible. Since the tape was thin and flexible, it easily conformed to the surface’s contours. The smooth plastic surface makes a great release surface.

Once the undamaged area was taped, I mixed a batch of 105 Epoxy Resin and 205 Fast Hardener with 406 Colloidal Silica until it reached a peanut butter consistency. I used the 406 Colloidal Silica because I wanted the mold surface to be fairly hard and dent-resistant. This way, I could ensure the mold maintained its shape throughout the project while rebuilding the opposite end of the ledge.

I applied the thickened epoxy to my packing tape, paying special attention to working the epoxy into the corners of the profile, removing all the air pockets. I applied enough epoxy to fill all the lows in the profile, which left a nice flat angle to apply my fiberglass reinforcement. The fiberglass stiffened the mold, making it much easier to work with and helping maintain the proper shape.

Using some scraps of 6 oz. fiberglass, I laid the first piece dry on top of my thickened epoxy. It was time to mix up a batch of neat 105 / 205. I brushed this on the fiberglass until it turned transparent, signifying it had been thoroughly wet out. Repeating this process, I ended up with three layers of 6 oz. fiberglass.

Since I had a little epoxy left over, I used it to bond the split part of the ledge back together. I brushed the neat epoxy onto the mating surfaces, then used masking tape to hold the split together snugly while it cured. 

After an overnight cure, the splash mold easily popped off the surface. I did a quick trim on the mold to get nice, clean edges. Then I removed any paint and bad wood from the rest of the ledge to prepare the surface for rebuilding.

Since our mold was made with epoxy, and epoxy bonds to epoxy, I also needed to prepare my mold surface. Using the packing tape again, I taped the mold surface so I could keep the smooth surface and it would release easily. Another option would have been to wax the surface, but since the packing tape is so simple (and works perfectly for the shape of this mold), I decided to stick with it.

I applied a coat of 105 Epoxy Resin with 205 Fast Hardener to saturate the exposed wood surface where I would begin my build up. Then, I added 410 Microlight to my epoxy mixture until it reached a peanut butter consistency. I built up the surface by dabbing the thickened epoxy onto it. Then, by placing the splash mold over the thickened epoxy, I could mold the details of the ledge into the epoxy. I started from the end overlapping the existing profile and gently pressed the mold down snugly as I worked toward the missing section. The excess epoxy that squeezed out was spread to fill any voids under the mold.

Once the epoxy cured, I removed the splash mold. The surface needed a little sanding to square up the edges and remove any little imperfections. Since my mold was too short to do the entire section with just one casting, I needed to be sure the mold would reseat snugly into the profile for the second round of filling. I repeated the process a second time to extend the profile to the end of the ledge. Then, it was on to the final shaping.

Finishing

I sanded and scraped the peeling paint from the rest of the door and inspected it for any significant damage I had missed. I didn’t fill every ding and dent but instead left them for the character of being a 100+ year old door. The last step for me was to prime the door. I chose a white primer for a clean, even base. I applied two coats of primer to the door. From here, the rest is up to my friend. His sad beat-up antique store find, is now a functional piece of character he can proudly add to his home. This project ran the gambit filling voids, making molds, crafting missing parts, sealing against moisture, and consolidating/bonding wood. The versatility of the WEST SYSTEM product line enabled me to tackle these diverse repairs and give this antique door a new life.