Need wood finishing advice!

[Joey]

Hi guys, I'm not a member of this group and this is my first post. Forgive me if I've posted incorrectly.

I have a question that I hope someone can help me with. I am restoring an old pinball machine and I need to refinish the plywood cabinet. It has a slightly rough texture with some very fine cracks in it. I've been able to sand it smooth while prepping it for latex painting, but the tiny cracks are still there. There are purely cosmetic minor cracks in the wood and it is not delaminating or loose. I need some way to fill them so that when I paint the cabinet, it will look as slick and smooth as it did when it came from the factory.

I have been looking at the following options:

1. Paint on an epoxy sealer. Allow it to fill the cracks and bind for two days. Sand smooth. OR
2. Find a thick primer (automotive high build primer?) that I can paint on that will fill the cracks. Allow it to dry. Sand smooth.

Is there another easier option? I've been consulting with someone who does wood boat refinishing and he says I need to do both 1 AND 2! I think that's overkill since the pinball machine doesn't need to be water tight and I don't plan to try to float it in a lake. Any advice would be great. I really just need to fill in these very minor cracks to make the cabinet look smooth. Wood fillers or putties are not an option because the cracks are very very shallow. Possibly half a mm. Plus, they run about 3-4 feet long in some cases. I need an easier paint on method.

[nailshooter41]

Welcome. Come by anytime. Fresh blood (meat?) is always welcome. ;^)

A couple of thoughts come to mind. If you are going to paint the cabinet with latex, you will probably have a problem (as in most likely) getting latex (water based) paint to stick to the epoxied areas for any length of time. It might work just fine, but you wouldn't want to find out after you get your machine reassembled, right?

If you are just filling tiny little cracks that are only 1/2 mm or so deep, the problem I think you will have is getting the filler material to stay in the crack. That tiny little crack may not be large enough for most fillers to remain sound, and if they don't adhere really well, the sanding and finish process will pop those tiny little threads of filler out.

For me, if the surface was to be painted, I would make the cracks a little larger with an awl, a marking knife, or something of that nature so they would hole more filler. I would make up a batch Durham's Rock Hard that can be easily worked with a trowel and skim a coat over all the cracks, overfilling slightly.

Sand this stuff carefully when dry, and you will never see your cracks. Paint adheres very well to it, and since the product really doesn't shrink, you won't see any repair lines if you sand correctly.

We use a lot of this stuff, and if you put it on a clean surface it is great. It is good for a lot of other things as well, and dries hard enough you can shape it with a sander, file, or even cut it with a knife if you want to carve it.

Best of all, it is cheap, very easy to use, and does what it is supposed to do. I have never found a finish, water or solvent based that didn't stick to this stuff when cured.

Hope this helps.

Others will be along after this post.

Robert

[nailshooter41]

Who knew... they have a website!

[Limey Lurker]

You need a polyester fine surface filler. This you will apply with a semi-rigid spreader which will push it into the cracks, and also make it more easy to control the thickness of the coat. It will also set ready for sanding in around 30 minutes. Don't buy the wood finishing type; buy the vehicle finishing type which are just the same but only half the price. A 4 inch spreader is probably the most comfortable size for the job. HTH

[SonomaProducts.com]

[Old Guy]

Hi Joey,

Under paint, I would use spackle, like for drywalls, to fill those cracks.

Goes on easily, sands quickly, and seems to stay in place.

Old Guy

[Pat Barber]

He just described "Bondo" which will work just fine for what you are doing.

Just remember to make "small" batches cause when it "sets", it sets in a hurry.

Limey Lurker wrote:

[dcamron71]

If you ask around on rec.games.pinball or rec.games.video.arcade.collecting they'll tell you the best thing to use is bondo. Don't use water putty, spackling or wood putty. I've done quite a few games over the years and nothing works like bondo. Everything else will eventually crack and ruin your nice paint job. Nothing sucks worse that moving a restored game and breaking off a corner in the process.

A few tips for working with bondo. Use only as much as you can spread in 3-4 minutes. After that it's unworkable. Leave a thin layer on top. Big globs are hard to sand. Don't get the crazy idea to "skim coat" the entire piece. Bondo is hell to sand because it clogs up your paper. When you sand, throw a bit of mineral spirits on a 8-10 inch area and hit it with a ROS. Use 60 or 80 grit paper. The mineral spirits will soften the bondo and keep it from gunking up the paper. It also makes the bondo smoother quicker and requires less paper. Your sandpaper will be toast within a few minutes so don't push too hard, work quickly and have about a dozen sheets of paper on hand. The mineral spirits eats through the glue that attaches the sandpaper to the velcro backing. Wear a respirator for applying bondo and sanding with mineral spirits. Inhaling that stuff might feel cool at first but when you get the twitches a few months later you'll be calling yourself stupid. No joking here.

Primer also works good for thin cracks. Put on several thick coats and dry sand it to a nice smooth surface. Should fill in hairline cracks. Anything larger can be filled with bondo.

[Peter Huebner]

Like a couple of other contributors I would recommend automotive filler. You can then sand, put the automotive thick primer over the top of that and wet sand for a super fine surface prep.

No way would I use latex paint on a pinball machine, myself. It's not wear resistant enough and you'll never get that high-gloss finish that you seem to be aiming for. Use enamel or acrylic spray laquer, and you might want to use an airbrush for a top quality finish (assuming you don't just have it all one colour). If you've never done it before, it's probably best to go to a auto spray shop, and see if you can interest one of the guys working there into the project, and get him to do the spraying for you in exchange for a crate of beer :-) If it's all one colour, get some automotive spray-cans and go to town with those ...

regds, -Peter

[Nitram]