TGIF: Fixing cracks, defects, and damage Sept 12, 2017

[kmealy]

 

 

There are a number of ways to repair minor damage or defects.   What you choose is somewhat dependent upon when in the finishing process it appears and the type of damage.

 

Dents

Dents can occur in the raw wood (AKA white wood) or at any stage of finishing, including in a piece that’s finished and in use.  You can often get out small dents, or at least 90% of the damage, by wetting the wood and steaming.  In white wood you can just add in some water, let it soak for a while and applying some light heat with an old clothes iron over a damp cloth. (If you like being married, don’t just sneak your wife’s from the sewing room.   I get mine as hand-me-downs when they need replacement).  In a finished piece you can do the same thing, but you may need to poke some holes through the finish with a pin.  If the wood has pronounced grain, like oak, you can reduce the pin prick look by hitting the open grain.

 

Gaps or cracks

 

Putty fill. 

There are a variety of putties, many in different colors and some even claiming to be “stainable.”   Well, they do stain, but they often don’t look like wood when it’s stained (two parts of the wood might not even take the stain the same.)  Perhaps a better approach is to stain and apply the first few coats of finish.   Then get a colored putty or add some dye to a neutral colored putty, or several, and match the color near the crack.  Apply the putty, let it dry, then apply the final coat of finish.

 

 

 

Sawdust and glue. 

This may or may not work all that well.   First, the sawdust will have significant portions of end-grain.  Second, the glue may inhibit or alter the amount of stain absorbed.   Some people have luck with this; I have not.

 

Liquid epoxy

Some people fill major damage such as cracks or knots with liquid epoxy.  Poured in and sanded level when set.  There is usually no attempt to match the color or grain but to use as an accent.

 

 

Post –finish damage

 

Wax sticks  

These are available in multiple colors.   It can sometimes help to warm them slightly to make them softer.  Again, you might mix several colors to mimic the wood graining.   Most finishes don’t stick well to wax, so plan on using this after the finish, not during.  Level by buffing.  A piece of paper grocery bag works well for this.

Epoxy putty or Polyester Filler

These are good for larger damage, but you’ll need a way to restore the color and graining.  The epoxy putty comes in sticks.  Slice off a bit, mix with your fingers until uniform color and press into the damage.  Depending upon the type it will harden in 5 – 60 minutes.   While still soft, you can shape with an old credit card and soapy water.   When partially set, it’s easy to trim with a chisel of razor blade.  When fully set you can smooth with file or sandpaper.   The polyester filler has a resin and a hardener.  A common brand is Bondo.   Mix together and apply to the damage.   Shape when partially set with a chisel or razor blade and when set, with sandpaper.   With both you’ll need to apply color to match.  You can do this with marker pens made for touchup, colored toners, artists’ paints, colored pencils, or pigment powders.   If the wood has open grain, you can restore this with very light cuts with a razor blade.   Apply top coat finish when done.

 

Burn-in repairs

You do burn in repairs with a special stick of resin.   You melt it with a heated knife and drip into the damage area.   The knife is heated in an alcohol flame, a propane torch, a special "oven" or with an electric or butane knife.  Then the fill is leveled with the knife.  I find a “burn in balm” (sort of like Vaseline) helpful to keep the resin from smearing and the finish from being heat damaged.  When level,  abrade even with steel wool or sandpaper.  I’ve seen a lot of people do these and no two seem to have the same technique.  I’ve developed what has worked for me.  When I was working full-time, I’d do these practically every day, sometimes up to 100 spots a day.  There are two basic kinds of sticks, the traditional ones (originally called “shellac sticks”) that are hard and glossy, and the newer soft ones that have a lower sheen and are more resistant to impact damage.   A good burn-in repair will be practically invisible if you get a good match on sheen, level, texture, graining, and color.

 

Quick tutorial:  But don't expect to get this right the first time.   It takes some practice.

 

 

Edited September 12, 2017 by kmealy

[Fred W. Hargis Jr]

I've tried that sawdust/glue trick several times, and each time it looked like a dog's breakfast. I gave up trying it altogether.

Edited September 13, 2017 by Fred W. Hargis Jr

[Gene Howe]

They epoxy and Turquoise is my go to for the sort of stuff I make. Sometimes, Just colored epoxy.

Timbermate is a good brand of putty, too. It can be mixed to alter the color.

I'm still experimenting with coloring Bondo. I'll get there....maybe. But, just as a filler and stabilizer, it's great. Used it in a resto project on a Baby Grand that had been severely abused by students. An auto body guy had invaluable info. Ended up using his recommendations for the brands and application methods for the black lacquer, too. Turned out great. 

 

 

Edited September 13, 2017 by Gene Howe

[HandyDan]

I liked the burn in repair best.

[kmealy]

6 hours ago, HandyDan said:

I liked the burn in repair best.

 

Yes, burn in repairs are good for small repairs.   If you get really large ones, they don't work so well.   I remember a cabinet guy watching me once.   He said he'd never mastered them.   I said that you need an hour of teaching and a bunch of practice.   He said he must be a slow learner because he'd been trying to do them for 10 years.    I think my record was over 100 in a day.   A guy was doing a remodel and a storm hit while the roof was off, he ended up pulling all the kitchen cabinets and damaged the heck out of them getting them in and out.    An architect who thought he was a contractor.   But when I was working for several stores and delivery companies, I'd do a handful nearly every day.  Either transit damage or showroom damage.