Filling Dents with Burn-In Sticks

Detailed advice from experienced pros on how to touch up dings and dents in furniture. November 8, 2007

I have 5-6 pieces of furniture for which I need to refinish the tops. All have scratches, dents, dings, gouges, etc., most of which do not go down to the white wood (i.e. no loss of color). I want to avoid stripping and starting over. I went to a touch up and repair class last week, and they taught the use of various burn-in sticks. This method seems extremely hard to do, and when I get a fairly good fill, it still looks terrible when I put topcoat on it. I am using NC lacquer, and I feel that the furniture has lacquer on it as well.

Does anybody really use these burn-in sticks successfully? If so, how do you do it, and how much practice does it take before doing real work? What other suggestions do you have? I know I can sand and just start layering on coats of lacquer, but I am looking for a quicker fix.

Forum Responses
(Finishing Forum)
From contributor D:
You didn't say which kind of burn-in sticks you tried. There's the EZ-FLO type (hard, shiny plastic), Plane stick (rubbery, dull plastic), and various wax sticks either from Mohawk or Konig.

You can paint in the dents and damages with clear lacquer and then sand them flush before your full topcoat. This method is not 100% because of issues with shrink-back and small area coating thickness, but the scars created are presentable.

I use the Plane stick and I use Wash Wax as a leveling agent. I coat over with the aerosol vinyl sealer and then topcoat. Spray lightly over your burn-ins and fills so the solvent doesn't attack them.

From the original questioner:
I use both E-Z Flo and the Plane-sticks. When I went to the touch-up class, I thought that the clear E-Z Flo would be the ticket to this type repair, but I just can't get the hang of leveling the burn-in without marring the existing finish, and I have a hard time getting the excess off. I also seem to leave pits and holes in it.

I also thought that a product called Blend-it would be the answer, but I really have problems with leveling it and topcoating it. No matter how much I sand it, you can still see it after the topcoat. The furniture I am refinishing is high dollar stuff with a heavy lacquer finish and has a high-gloss sheen.

From contributor J:
E-Z Flow burn-in sticks are what I would use. If you're new to using burn-in tools, practice on some scrap pieces first and get accustomed to the technique of doing a burn-in. Be sure to clean the surface with wax wash or mineral spirits before starting the repairs. Use plenty of burn-in balm for the clean up process. You can also put some masking tape around the repair if you're having trouble cleaning up the burn-in and leaving marks in the finish. Level sand the repair with 400 wet/dry sandpaper. Apply 2-3 coats of finish up, then 2 light coats of burn-in sealer. Spray an overall coat of E-Z vinyl sealer on the entire piece, then topcoat. If you are planning on wet sanding, rubbing and buffing the table, you won't need to use the finish up and burn-in sealer and the vinyl sealer. You should be able to get enough lacquer on the part to cover the burn-ins before you rub them out.

From the original questioner:
Thanks for the info. It is encouraging to know the fill sticks can be mastered. Have you had any luck with Blend-It?

From contributor R:
Something to consider - try spraying on some retarder that has been mixed in lacquer thinner. Many of those scratches will flow together and won't be noticeable once your topcoat has been applied. I usually do this procedure on a Friday so I don't have to deal with the smell, and come Monday the solution is usually ready to work on.

From contributor M:
1) What type of burn knife are you using?
I would recommend Butane M120 cordless from Mohawk because it has heat control. Low heat allows you to take your time with burn-ins. For years I used and saw most professionals use electric knives and electric ovens, which are extremely difficult to use because of their high heat. Now the only time I turn up my butane cordless knife to high heat is when I have a large job with hundreds or thousands of burn-ins.

2) Look at the scratches carefully. Sometimes the edges of the damage are white in color (torn finish), and after the burn-in, the white edges will still show around your burn-in. I like to touch up repairs prior to burn-ins if needed. This will allow you to polish the top surface without top coating. So create a color with Blendals powders or use Mohawk toners and apply it with a small artist's brush. It does not need to be perfect; any finish that gets on the top surface will be polished off or sanded off later. Now let the finish dry for an hour and start burning in your lacquer sticks.

3) Sand your burn-ins flat with 320 and 400.

4) Use the Mirca Abrolon pads with water and rub entire top surface by hand. Start with 1000, then 2000, lastly with 4000 grit and finally hand polish your finish with water and rottenstone. Hand polishing should only take 20 - 30 minutes max on a 3í x 6í desk top. Do not use a machine buffer. Machine buffers will soften and re-melt your burn-ins.

From the original questioner:
I am using an electric knife that I got at the touchup workshop. I have been practicing, and I am getting better, but I still am not happy. I may look into the cordless knife if I continue to do touchup jobs (custom furniture is my main business). I am having some trouble sanding the burn-ins level. It seems that the burn-in stick material is harder than the surrounding finish, so I am getting some sand-throughs. Not good. I guess I will practice some more. Thanks everyone. There was some real helpful advice in this thread.

From contributor T:
It sounds like you might be burning in too much stick in your repairs. If you are trying to level it with more than 3-4 passes of the knife, try using less stick to begin with. After leveling, if it seems to have a low spot, add just a touch more to the spot. Add more burn-in balm and try again. Don't give up - you'll get the hang of it.

From contributor D:
I use the traditional knives:
Curved flexible #62
Extra Flex Straight #517
Flat Rigid (straight) #K12

I use burn-in balm and the Plane Sticks. The knife I use most is the #62 and after applying the burn-in, I try to use the edge of the knife to shave the excess.

For heat I use a small propane torch. These tiny propane bottles are green and I think they come from Home Depot and the like. I think it is a Coleman, I don't recall.

Leveling the burn-in further is accomplished with 600 - 1200 grit wet/dry lubricated with either Mohawk's aerosol Wash Wax or with Rub Cut oil (mineral oil). The Wash Wax levels the fill more quickly because there are some solvents in the mix that are more aggressive (not at all harmful to fully cured lacquer finishes).

I seal in the fills with Mohawk's aerosol pre-catalyzed sanding sealer. I topcoat with light coats of clear, whatever sheen I need. If I am spraying a rubbed piece, then I need to think through my topcoating/spot repair. Maybe I need a full surface topcoat or maybe I can get away with spot spraying.

If the dents are deep/large enough, then I would want to use either Bondo or epoxy sticks to fill them. I can color them with Blendal Sticks (post cure) or more traditional coloring methods (Blendal powders). Make sure that you do as little sanding and that your filling technique leaves you with the most flush surface you can get. For epoxy stick, I use Formica samples coated with Wool Lube/water so that as little as possible of the stick will adhere to my flat Formica sample (I use this to press the fill flush and also to scrape the excess away). I also use my Flat Rigid knife to try to level my epoxy fills.

CA glue (don't use the activator) can also be used successfully for clear fills. You don't have much control over their leveling until after they cure, though. Sand flush and topcoat.

A note about sanding... Follow through with your sanding sequences and final sand with steel wool (lightly). That's your best shot at not having sheen differences, especially in original coats which have been formulated with waxes in them.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor L:
Try using Mohawk edging sticks. I grew up on burn in sticks for over thirty years. The edging sticks can be melted in with a lighter, sanded down with the back side of 400 wet or dry and dialed in with 400 - wet or dry with water (spit for the old timers). You can get it perfectly level and quickly and then seal , touch up and seal/finish as usual. Iíve done it for decades with excellent results and it makes a burn in iron obsolete. Itís somewhere between a burn in and a patchal pencil. Give it a try; I love it for quick and quality touch ups.

Comment from contributor W:
After this lengthy discussion I have only one thing to add. Make certain that the piece is finished in lacquer and not shellac for if finished in shellac and you top coat with any lacquer or vinyl it will not match well. To test for shellac simply dampen a hidden spot with alcohol - if it becomes soft you have shellac finish which must be topcoated with shellac.