Dinged, finished spruce top - Can I steam it?

[Chuck Tweedy]

Oh, I'm feeling very low right now.
Just moved one body out of the dry-box to glue down the bridge, and moved another in. The door crashed down on the top of the instrument!!!
It is red spruce finished in Seagraves lacquer. The finish is pretty much all buffed out and everything, just needs the bridge.

Question: I've heard of steaming out dents in finished wood, but have not tried it. Can I?

This thing is pretty deep, so just drop filling is out of the question. Do I need to poke holes in the finish to allow water in? I can imagine putting a wet string down the valley and hitting it with a soldering iron, but the wood will not be wet except along one edge where the finish is ripped.

After pulling the dent I can hit it with my air-brush to fix the finish, but ... how to pull it??

Here's some pix...

[Steve Senseney]

Steam right through the finish.

You might pad areas around to prevent steam from treating the entire top.

Steam it once, let it set a while (one or more hours) and look at it. Steam it again if you are not as high as you want. It should raise the fibers nicely.

FInishing will be another problem.

If it was Shellac, it would hide the repair nicely!

[Clay Schaeffer]

Hi Chuck,
If the fibers aren't broken you may be able to remove the dent by steaming. It may make the finish cloud up a bit but a little light sanding and respray should bring it back.

[Mario Proulx]

As has been said, steam through the finish. It will rise higher than the surrounding wood, then leave it alone for a couple of weeks. Yes, 2 or more weeks! You must allow it to return to equilibrium on its own. Otherwise, if you attempt to level and polish it too soon, you'll have a permanent depression when the wood does go back to equilibrium.

Edit to add:

If after a few weeks, the area that you raised is still slightly higher than the rest of the top, don't level it by sanding. Instead, --push-- it back level. Use the back of a chisel, a very flat block of hardwood, or something similar. Only now can you think of beginning to repair/level the finish; not before.

The gain some experience with these techniques, take some scraps of spruce(the off-cuts of this very top would be ideal), and make similar dents in it, then practice steaming them out. If you wish to gain really good experience, apply the same finish to the scraps, then make dents in it and practice repairing them.

[Chuck Tweedy]

Thanks guys.
I've steamed dents out of unfinished wood, and I've been very successful with that. It's just the finish that that has me scratching my head.
I have 2 other instruments to complete, so I can afford to wait plenty of time before repairing the finish.

I'll try to steam this dent later today and report back.

[Jason Rodgers]

I have no advice, just a sad face for you

And a request to post progress photos, so those of us who will no doubt one day be in your shoes can learn. I'd like to see what cloudy finish looks like, and how badly. And if the dented area does in fact bulge above the surface, as Mario predicts it might, how much.

And a suggestion to put the hinge on your dry box door on the bottom, like an oven.

[Chuck Tweedy]

Things have gone better than expected.
I prepared well, I had all the materials I needed, and I think I had a reasonably innovative idea that I followed.
The idea was to contain the steaming to just the ding, and as little surrounding area as possible.
I did this by masking off the surrounding top (as Steve suggested), I moistened only the ding, and I applied very directed, very concentrated heat.

I have an old spool of carpet thread I got from my Dad. It's probably from his Mom who worked in the mills in Laurence Mass.
I cut little pieces about as long as the ding, and soaked them in water. The thread is slightly polished, so it took a while to soak up water and puff up.

[Chuck Tweedy]

While the thread was soaking up water, I masked off the top with green masking tape. Notice, I pressed the tape down where it covered itself so there were no gaps for steam to shoot under.

[Chuck Tweedy]

I let the wet thread sit there a bit to _maybe_ soak some water into the substrate wood.
Then I hit it with a hot soldering gun that I happen to have a blade tool for.

[Chuck Tweedy]

There was a very minimal hissing as the water steamed off, and the thread ended up scorched.
Oh yea - I was very careful to ONLY hit the thread with the gun. NOTHING else.

[Chuck Tweedy]

I hit it several times with 3 different pieces of thread. Once in the middle and at the far end. Then I really heated up the spot by the binding, because that was where the ding was the deepest.
After this, the opening in my mask looked "matte" but puffed back up to the level of the surrounding wood.

[Chuck Tweedy]

Taking off the mask I could see that I had contained the damage to (mostly) one earlywood line.
And the ding looks perked up.
Yes, this is a 4-piece top.

[Chuck Tweedy]

Checking with a straightedge, there does not appear to be a gap at the offending location any more.
WHEW!!

I wish I'd never bonked the guitar in the first place, but this was a very productive repair learning experience!

[Douglas Ingram]

Excellent save!

[Chuck Tweedy]

Thanks Doug!
At this point I'm guardedly optimistic. All I can really say is that it looks like I only need to fix the finish and I'm done.
I'm really surprised at how well it worked. Almost ... not even "almost" ... better than dent steamings I've done on raw wood. Tho I've never really been this hyper-concentrated on getting it right.
I'm crossing my fingers and letting it hang for now.

[Jason Rodgers]

Nice save! And now you'll be moving the drybox door hinge to the bottom with a magnetic catch on the top? I just looked back at the original thread and pictures and saw the dowel propping the door open: you bumped that with your left hand and brought the door down, right? That would have sent me through the roof! You could also install a simple gate hook on the bench leg beside open door to hold it open more securely.

[Randy Roberts]

Nice work Chuck, and thanks for posting this. I've got a bunch of these to try to get out of a cedar top ( although I didn't put them there) and have been putting it off for 3 years or more from lack of cajones.

Is that white area above the tape on the post- steaming picture just a reflection, or did the steam somehow reach that far up ( I don't see the spot in the subsequent picture after removing the tape.

I hope you will also post the finish repair when you do it. Your pictures are so clear that it really helps understand what you are doing so far.

Jason, if the hinges were on the bottom it would be too easy for the baby ducks and chicks to escape.

[Chuck Tweedy]

Thanks Randy & Jason.
Jason, I'm actually very happy with the incubator's door system. It does, in fact, have a gate-latch that holds the door up - and it's connected to the bench leg, just as you suggest. However, if the operator does not latch the door up and relies on holding it with his butter-fingers then it can fall and teach that operator a valuable lesson.

Randy, the light spot on that picture (masked area after steaming) is just a reflection. The steam only traveled under the tape about a mm or so.

BTW, all these pictures are from my phone. It is a 3 year old HTC Inspire. It sometimes does a real good job.
I crop and size the images with GIMP2 (which is awesome ... and FREE).

I'll keep this thread alive to follow the progress. Right now it's hanging in the rafters.

[Jason Rodgers]

It does, in fact, have a gate-latch that holds the door up - and it's connected to the bench leg, just as you suggest.

Ah, brilliant! Then my work here is done!

[Mario Proulx]

Well done!