A quick raised panel finishing question

[gsmittle]

I'm almost ready to assemble my first raised panel. I finished the panel first, but what I'm wondering is should I finish the frame before assembling, or wait until after the frame/panel are assembled?

g.

[Black wallnut]

Wait or your glue may not bond properly.

[JimD]

I like to finish the panel and the inside edge of the frame first, then assemble. You do not want finish on the area you will glue, as black walnut said, but it is a lot easier to clean squeezed out glue from wood that is finished and glue really messes up finish if you don't get it removed. I don't finish the large surface areas because I sand the frame flush with a ROS after assembly and then finish it.

My sequence of events is to make the frame, measure it inside for the panel dimensions, make the panel, sand the panel and inside of frame, finish them, then assemble, then sand the frame and finish it. If I am fitting the door to the cabinet, I do that before sanding and finishing the frame. Sometimes I shoot the whole door with a coat of finish at the end - the panel sometimes will get scuffed.

Jim

[cabinetman]

If I make the doors, and I use solid wood, I'll finish the panel, assemble the frame, and then pin the panel at the top and bottom only in the center. If I order doors, they come assembled, and are pinned the same way. I'll just finish them intact.

If I make the doors and use ¾" plywood for the raised panel, or use ½" or ¼" plywood for a flat panel, I'll glue the panel to the frame, and then finish it.

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[chopnhack]

If I order doors, they come assembled, and are pinned the same way. I'll just finish them intact.

Are the premade doors so stable that unfinished wood never reveals? Always wondered about that..

[cabinetman]

Are the premade doors so stable that unfinished wood never reveals? Always wondered about that..

By "reveals" if you mean along the seated edges of the panel in the groove, no, I haven't had that problem that I can remember. If stained, it seeps along that edge, and I guess that enough gets under there to mask any "reveal" if the panel moves one way or another. Being pinned, limits the panel from having a free reign of a total side to side travel.

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[woodturner]

I'm almost ready to assemble my first raised panel. I finished the panel first, but what I'm wondering is should I finish the frame before assembling, or wait until after the frame/panel are assembled?

There are many different opinions regarding what to stain or finish before assembly. The right one for you is what works for you.

The primary concern is staining and finishing the edges of the panels before assembly. If the edges are not finished, when the panel expands and contracts with seasonal changes in temperature and humidity, the unfinished edge of the panel can be exposed. A stained panel with an exposed unfinished edge is unsightly and draws the eye, so this is best avoided. This is more of an issue for a solid wood panel than a plywood panel, but plywood panels are affected to a lesser degree.

Finishing the inside of the groove for the panel can cause the panel to bind and then split with the seasonal changes. The issue is that the finish on the panel and groove tend to stick together and limit movement of the panel. Curing finishes that cure to a harder surface such as catalyzing lacquer don't have this issue very much because they aren't really "sticky". Many drying type finishes, like shellac, oils, varnish, poly, etc. will have this issue since they remain softer and "stickier".

There is a local shop that makes drawers and doors for cabinets that many of the local woodworking shops use. What they do is mill all the pieces, stain and finish the panel, stain and finish the rails, then assemble the door. They use HLVP spray equipment for finishing and have better control of overspray, so they don't mask anything. A tiny bit of overspray gets in the panel grooves and on the tenons, but it's not enough to affect panel movement or glue joint strength.

Another source of controversy is whether or not to pin the panels in the center. The argument for this practice is that it keeps the panel centered in the frame, so you don't have to push the panel back into place if it ends up migrating to one side. The down side is that the pinning can cause the panel to split over time. I have never pinned panels and have not had a problem with the panel migrating. If you are concerned, though, you can get compressible rubber balls that are put in the groove before the panel is inserted. These balls keep the panel centered without any pinning, so the panel is less likely to crack.

Regardless of which way you do it, make sure the panel is free to move in the groove when assembled. You don't need a "loose" joint, but you should be able to move the panel with finger pressure. If the panel binds, it will likely split with the seasonal changes.

[cabinetman]

There is a local shop that makes drawers and doors for cabinets that many of the local woodworking shops use. What they do is mill all the pieces, stain and finish the panel, stain and finish the rails, then assemble the door. They use HLVP spray equipment for finishing and have better control of overspray, so they don't mask anything. A tiny bit of overspray gets in the panel grooves and on the tenons, but it's not enough to affect panel movement or glue joint strength.

This is absolutely not true. It doesn't matter what method is used to do the finishing, any stain or topcoating will affect the bonding of a glue joint. I wouldn't do that even with trying to mask off the areas to be glued. Unless an area is totally inaccessible after assembly, finishing should be done last. That allows the opportunity to do a final dressing to any areas that may need it before using stain and a topcoat. That's why it's called "finishing".

Another source of controversy is whether or not to pin the panels in the center. The argument for this practice is that it keeps the panel centered in the frame, so you don't have to push the panel back into place if it ends up migrating to one side. The down side is that the pinning can cause the panel to split over time. I have never pinned panels and have not had a problem with the panel migrating. If you are concerned, though, you can get compressible rubber balls that are put in the groove before the panel is inserted. These balls keep the panel centered without any pinning, so the panel is less likely to crack.

Spaceballs can minimize solid wood panel movement. Pinning has been the choice of doormakers long before spaceballs were ever used. I can't count the amount of doors I've pinned, likely in the thousands. Pinning by itself, if done correctly doesn't cause the panel to split.

Using the proper materials, and acclimating the stock to be used minimizes the propensity for expansion and contraction. Most installations provide a constant environment for woodworking to stabilize. The "seasonal changes" might be an issue if the subject pieces are exposed to changes in temperature and humidity. Those differences could be from having a piece of furniture that has lived on the east coast, or in a humid climate, and then shipped to a very dry climate with very little humidity. But, prudent thinking doesn't say, that if the season changes by one month ending and another one started that the wood is going to expand and contract.

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[JimD]

My count of raised panel doors is only dozens, not thousands, but I have almost never seen a need for space balls or pinning. My panels generally were secure in the grooves without spacers or fasteners. These days, the rare one that isn't would probably get a pin in the form of a pin nail or two.

I've taped the tenons and sprayed finish before assembly but generally I do not spray the frame parts before assembly because of the potential to affect the joint as C'man suggests. I will use a brush or wipe on a coat or two on the inside edges (nothing in the groove for the panel) before assembly as stated earlier. Panel might finished the same way or sprayed depending on how many I was doing.

[cabinetman]

My count of raised panel doors is only dozens, not thousands

I have to admit...I never counted, I just ventured a guess. I might have exaggerated a bit...it might have been only 900+. When I was a kid, my father said..."If I told you once, I told you a million times, don't exaggerate".

I tell it like it is from doing the work. I don't embellish facts or misrepresent myself.

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[woodturner]

I've taped the tenons and sprayed finish before assembly but generally I do not spray the frame parts before assembly

Whether to finish before or after assembly is another controversial topic among woodworkers.

The arguments for finishing before assembly are that it prevents glue contamination of the wood and ensures all of the wood is finished. Even carefully placed glue can migrate in some cases, particularly the resorcinol glues often used in commercial shops. If the piece is stained and finished after assembly, glue splotches can result.

Finishing before assembly also allows all of the wood to be finished, which cannot be achieved in many cases on an assembled piece. The issue is that as the finish cures, it shrinks slightly and can warp wood. This is particularly a problem on larger flat surfaces such as a table top. If the top of the table is finished and the bottom is unfinished, the top can warp significantly.

The argument for finishing after assembly is that it prevents finish contamination of the wood, which can result in weaker joints. With HVLP spray equipment and even good conventional equipment, it's not difficult to avoid overspray on the tenons, so it's essentially a non-issue. Masking also solves the problem, but adds time and labor to the process, so commercial shops tend to avoid it. Another option is to cut the joint after finishing, for example cut the tenon on the rail after the rail is finished. Care is required to avoid damaging the finish, but harder finishes like catalyzing lacquer reduce the issue.

Whether commercial shops finish before or after assembly is largely a matter of practicality. If they are making pieces like tables that can easily be fully sprayed after assembly, they often spray the finished piece. If they are making pieces frame and panel doors where they cannot finish parts such as the edge of the panel after assembly, they usually opt for finishing before assembly.

For home and "one off" shops, what high volume commercial shops do is largely irrelevant. Few home shop woodworkers spray catalyzing lacquer and epoxy finishes or use resorcinol glue. As a result, different processes often work better in lower volume shops.

As I mentioned, the local "goto" place for frame and panel doors and drawers finishes before assembly. Doesn't mean it's "wrong" to finish after assembly, that is just how they do it. BTW, that shop is very willing to give tours and talk about their process. The local woodworkers' guild visits there every few years. They are very happy to share and discuss their techniques. They have optimized their process to make these items, and can produce them for less than other shops. The owner of a high end furniture shop commented on the last visit that he can hardly buy the materials for the price they charge for the completed drawer or door. Probably why they essentially "own" the market in this region and are making thousands of pieces a year.

Another issue that will vary by location is seasonal expansion and contraction. The degree of fluctuation varies with geographic location. When I lived in the arid west, the humidity and temperature changed very little day to day, and wood movement was less of an issue. When I moved to the east coast and later mid Atlantic, it was more of an issue. For example, the panel in a typical 30" kitchen cabinet will expand and contract in width 1/8" to 1/4" in the course of the year as the humidity and temperature changes.

For smaller shops using finishes like shellac, varnishes, and oil applied by brush or cloth, overspray is not an issue. For example, my primary product is period reproductions and furniture in a "period style". I finish almost exclusively with brushed shellac, French polishing, and similar traditional finishes and primarily use hand tools on parts that are visible in the final piece. I do finish frame and panel doors before assembly and that has worked well for me, for my shop.

This is just my experience and what I have learned in my last several decades of woodworking. Others may have different opinions, and that is OK. As I said earlier, what works for the woodworker is what is best for them. We each live in different climates, have different skill levels, and have different equipment available. They key is to figure out the process that works best in your own shop.

[cabinetman]

The arguments for finishing before assembly are that it prevents glue contamination of the wood and ensures all of the wood is finished.

The argument for finishing after assembly is that it prevents finish contamination of the wood, which can result in weaker joints. With HVLP spray equipment and even good conventional equipment, it's not difficult to avoid overspray on the tenons, so it's essentially a non-issue.

It is an issue, because any finish on joined areas with glue are compromised.

For smaller shops using finishes like shellac, varnishes, and oil applied by brush or cloth, overspray is not an issue. For example, my primary product is period reproductions and furniture in a "period style". I finish almost exclusively with brushed shellac, French polishing, and similar traditional finishes and primarily use hand tools on parts that are visible in the final piece. I do finish frame and panel doors before assembly and that has worked well for me, for my shop.

Post some pictures of that finish. Actually, any pictures of the work you talk about would be nice.

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[leehljp]

It is an issue, because any finish on joined areas with glue are compromised.


Post some pictures of that finish. Actually, any pictures of the work you talk about would be nice.

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Cab, let it go. If someone posts something that you disagree with and particularly WT, make a comment if you will, then let it go. Don't make it a p…. contest.

[cabinetman]

Cab, let it go. If someone posts something that you disagree with and particularly WT, make a comment if you will, then let it go. Don't make it a p…. contest.

It's discussing methods and procedures...not a p...contest. I made my comments which were courteous and polite. When there are continuing comments that I disagree with, I offer my opinion and address the issue.

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[Stytooner]

There is more than one way to skin a cat. Let's agree that there is more than one way to do things in woodworking and do as Hank suggests.
You made your point.