Pre-finishing wisdom help

[Scott Winners]

Tell me this gets easier. Please. I drank the kool-aid.

I am pre-finishing my current project so when I am done with assembly all I will have left to do for finish work is the exterior. I have made my first dumb mistake. I still believe in the idea of pre-finishing, and I came at with no small amount of fear of screwing up. I planned and planned and planned, and I have screwed up.

I am building a wall hanging cabinet. The inside back wall is painted one color. The inside walls, floor and ceiling are bare wood with oil and wax. The exterior case will be a different color. I got the dovetailed case glued up, and those four pieces oiled and waxed on the interior. I got the bottom piece of the back wall painted and installed - but I forgot to cut a tongue or a groove in it to mate with the rest of the pieces of the back wall.

I can pull this put of the fire by cutting most of the groove I need with my plow plane, but I am going to need assassin level work with my dovetail saw where the plow plane can't reach. I only got assassin level skill with my dovetail saw about three days per month. You see the problem.

What mistakes have been made that I can learn from the experiences of others before I do them again? What mistakes am I doomed to make on my own regardless of your various remonstrations?

What is a good tape to use to cover tenons when prefinishing table aprons? I see that one coming.

How do you keep finish out of the mortises in table legs so you have good area for glue up later? I see that one coming.

What is going to cause me (Navy) to string together profanities in a way God almighty has never heard before, and how do I prevent that?

Thanks. This is a good idea and there was going to be a learning curve, but I am committed to getting this right.

[Ken Krawford]

Scott I'll tackle the mortice/tenon part and leave the rest for others. I just cover the tenons with blue painters tape. Easy peasy. For the mortices I cut loose tenons and slip them temporarily into the mortices. Cut them loose enough so that they can be easily removed after finishing. I've done this on many projects and works great.

[Darrell Bade]

It is a different thought process and often takes longer even though there are advantages. Painters tape where glue goes. I pre-finish sometimes, it takes a thought process of running through the assembly in your mind or dry assembly first. Even doing that I sometimes miss something and use those choice words (I didn't serve but work for them so I am somewhat prepared).

[Phil Mueller]

To protect mortises I have a few sizes of that foam backer rod. Cut a piece to fit in tight, finish, and pull it out.

[Kevin Jenness]

What mistakes have been made that I can learn from the experiences of others before I do them again? What mistakes am I doomed to make on my own regardless of your various remonstrations?


I'll try to answer the question I would be asking -How can I avoid missing an important step in construction?

Do a complete drawing, then make a list of tasks needed to make the project look like the picture. Build it on paper and check off the tasks as you go.

[Prashun Patel]

Don’t run from mistakes. Embrace them. That’s where you get your experience and improve your skills.

Highlight mistakes as war wounds and be proud of them.

You have to make your own mistakes. Don’t stress over them though.

[Jim Becker]

When you go to remediate the missing rebate/groove, score the line with a knife first to reduce the risk of damaging the finish.

I use normal blue tape for masking off glue surfaces for pre-finishing. Tape and a sharp blade works well for this. To get right to an edge, let the tape go beyond it, press it down and then run the sharp blade along the edge carefully to remove the excess tape. Burnish the edge of the tape down for a good seal. Around mortesis, create tape "stickers" that are just a proverbial hair smaller than the actual glue area...apply the tape, press it firmly, use squares and other measuring tools to use a blade to cut the tape to the exact shape and dimension, being careful to not cut beyond the area that will be hidden by the intersecting component.

[Stan Calow]

Change your mindset. Consider the skill of covering your mistakes as the true sign of craftsmanship.:)

[John TenEyck]

Plenty of good advice above, nothing to add on that topic. However, contrary to many, I prefinish only when there is no other option, and when I have to I dry fit everything and adjust parts as needed to minimize the chance of having to rework anything after glue up. That's my biggest concern about prefinishing, having something go out of alignment during glue up such that I have to sand/plane/etc. something to make it look right, or live with a proud this or that.

Good luck with the fix.

John

[Jim Becker]

I agree that there can and should be some selectivity about what components/assemblies get pre finished for the reason that John mentions. For cabinet boxes, it's almost a no-brainer to me. For complex assemblies, I'd have to take caution because of the potential for additional fitting after glue-up.

[Tom Bender]

Make a mockup of the tricky bits and practice finishing on them.

A finish that lends itself to repairs makes it much easier.

[Scott Winners]

My project is finally "done-ish" (neanderthal haven) the single biggest mistake I made was doing my samples with milk paint on horizontal surfaces, knowing at the time I would be applying milk paint to vertical surfaces. Once the project was assembled, ie the 4 case walls dovetailed together, I would be setting the case on my bench on its "back" so all the outside walls to paint were going to be vertical, but I did my testing with flat horizontal boards. Enormous mistake, cost me a week of shop time.

And I tried a new technique halfway through, decided to incorporate it and somehow managed to dodge a bullet.

Also, I exuberantly finished the outside of some drawers before fitting, and then after the drawers were planed to fit I had to finish the outside a second time.

Once bitten, twice shy, I still think prefinishing inside surfaces while it is 'easy' is a good idea, and I am glad I learned a couple dozen things, but prefinishing exterior surfaces before glue up and fitting seems to be wasted time.

[Lee Schierer]

When you go to remediate the missing rebate/groove, score the line with a knife first to reduce the risk of damaging the finish.

I use normal blue tape for masking off glue surfaces for pre-finishing. Tape and a sharp blade works well for this. To get right to an edge, let the tape go beyond it, press it down and then run the sharp blade along the edge carefully to remove the excess tape. Burnish the edge of the tape down for a good seal. Around mortesis, create tape "stickers" that are just a proverbial hair smaller than the actual glue area...apply the tape, press it firmly, use squares and other measuring tools to use a blade to cut the tape to the exact shape and dimension, being careful to not cut beyond the area that will be hidden by the intersecting component.

This is what I do.