# Finishing construction grade lumber?



## deadherring (Jan 10, 2012)

Hi,
I am nearly finished with this bunkbed build for my boys: http://woodgears.ca/bed/bunk_bed/plans.html.

I used construction grade lumber but milled it all with my jointer and planer. With all the time I have into the project I am hoping to finish it real nice. The wife was hoping for a dark stain, but if that wont go well with this lumber we can go lighter too.

I have heard that construction grade lumber can be hard to finish nicely but I am looking for input on how to finish it, including how much to sand (up to what grit?), the best finish type, in between coats treatment, and poly type/coats. 

I've heard dyes might work well? Also is wood conditioner a good idea first too?

Thanks in advance.

Nathan


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## Trav (May 30, 2011)

Looks like a fun project Nathan. You didn't mention the species of the wood, or at least I missed it, in your post. That info will be very useful in giving you the advice you seek. Also, ya got any pics? We would love to see your bed.


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## Wendel17 (Apr 20, 2009)

Personally, i've never tried dye stains, so I'm not in a position to give you advice on that.

A conditioner is probably ok. I've used that with success on maple and pine. I usually go with an oil based stain followed by oil based poly if I'm hand finishing. For sanding, I usually take it to 150-180 max pre-stain. 

After the poly goes on, I go with 240 or 320 between coats.


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## Wendel17 (Apr 20, 2009)

Sorry, I forgot to mention...sanding between coats of poly, I do it by hand. Very lightly. Just enough to smooth it out, but not enough to take any colour out.


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## bauerbach (Mar 25, 2012)

I assume this is probably pine 2x4s? the results vary... I think theres a reason no one reaches for pine over oak or maple, or whatever else. The grain is kind of fat, and it doesnt absorb the stain particularly well. theres probably a better explanation, but thats been my experiences with it. 

You will get fairly drastic differences of dark and light areas, each being broad and very noticeable.

a decent example










Not that its necessarily a bad thing... it can be kind of a rustic look with a dark brown stain.

I havent done it often, but when I have, same as any other wood. 1 coat of stain, a few coats of poly, sand in between, or not... depends how much I care about the finish on the piece.


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## Bill White 2 (Jun 23, 2012)

Gonna be a crap shoot.
I'd seal with shellac (Zinsser Seal Coat) diluted 50/50 with DNA.
Stain is iffy at best. I don't use MinWax EVER.
You're going to have to check moisture levels before ya do anything.
Toning the finish with TransTint (color of your choice) might be the best option.
Bill


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## epicfail48 (Mar 27, 2014)

Depends on the species of lumber. If its spruce or fir framing lumber I usually have good luck by sanding through 120-180-220, stain with whatever you choose and finish with whatever. Usually works fine for me. If its pine, burn it


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## Trav (May 30, 2011)

If it's pine I suggest the use of a gel stain


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## Steve Neul (Sep 2, 2011)

You can finish construction grade lumber just fine. The thing to do if you intend to use an oil stain especially if you plan to stain dark is to use a wood conditioner. Assuming the wood is a mixture of spruce, pine and fir, all of which is prone to go blotchy so the wood conditioner will help. The conditioner will make the wood harder to stain dark so you might purchase a darker color stain then you would otherwise. If the color still isn't dark enough you can supplement the color with a dye stain. It's best sprayed though. Mohawk Finishes also makes toners in aerosol cans you can also use to supplement the color. Once you get the stain to your liking you can finish it with the clear coat of your choice. For bunk beds which will take a lot of abuse I would recommend an oil based polyurethane.


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## GeorgeC (Jul 30, 2008)

The finish I would use would be a good grade of paint.

George


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## Brian T. (Dec 19, 2012)

Construction lumber has been run through a planer mill at 8,000rpm with ceramic blades. Explain the reason(s) for scruffing up and destroying the planed surfaces with sandpaper. You need smooth? It was done for you.

Construction lumber here is COFI/Council of Forest Industries SPF (spruce, pine fir), nobody makes any distinction. Kiln dried to 24%MC = it is not hardwoods. The AAC (Annual Allowable Cut) is about 40 million cubic meters, a meter is about 1.2 yards.

My best results were with simple semi transparent oil base walnut stain cut 30% with mineral thinner. 1x12 then built up as 60 x 12 bottle bins in a wine cellar.
Drink Canada Dry.


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## bauerbach (Mar 25, 2012)

sounds like he may have planed it himself, maybe to square off the edges, get it to tighter tolerances, take out a curve, ect.


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## deadherring (Jan 10, 2012)

Thanks for the replies--lots to consider here. For those asking the type of wood--I'm not sure, it's whatever they have in the construction lumber section of Home Depot.

To the person who was asking why I'd be sanding after having run through the planer/jointer--I was wondering about sanding after planing/jointing  considering the wood feels quite nice and smooth to the touch after milling--all the lumber was run thru the jointer and planer. (I'm pretty new to this woodworking thing). It sounds like you are saying no need to sand--just go ahead with the finishing?

And for the person who asked for a pic, here it is, this was taken before I added the slats and still need to add the top rails and ladder:










Thanks,

Nathan


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## Steve Neul (Sep 2, 2011)

Good looking bed. I bet your kids will enjoy it a lot especially knowing you built it. 

I was taught the marks made by a jointer or planer were a defect which should be sanded out. I always belt sand these marks off before going to an orbital sander.


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## Trav (May 30, 2011)

Looks great!

I too sand after the planer. Mine cuts real smooth, but not smooth enough. If you are going to skip this step I recommend finishing a test piece. On the other hand I never sand the glue face of the jointer.


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## bauerbach (Mar 25, 2012)

in all honesty, paint may not be a terrible idea... 

when in doubt. grab a leftover peice of wood and throw some stain on it, see if it suits your taste.


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## deadherring (Jan 10, 2012)

Thanks guys--the kids are excited, and the wife, well shes a little surprised it came out looking ok and pretty sturdy. To be honest, so am I a little  My previous projects have been much smaller in scale and less dependent on being really sturdy.

I ordered some dyes and am going to test out a few things to see what works best on scrap

Nathan


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## pweller (Mar 10, 2014)

I've had the best overall luck with water-based dyes followed up with oil-based poly. I've found, if you use oil poly over oil stain, that the stain creeps up into your poly - so when you try to sand it you remove color, thus botching the job. If you use oil poly over water based dye, the dye won't creep into the clear coat, so sanding won't remove any color.

I'd also suggest you consider a toner, which is kind of like a thin semi-transparent coat of paint. You'd do dye first, poly next, toner next, then final poly. The toner will probably obscure the grain slightly, and may help even out the color in the end. And, you can remove the toner if you don't like it before applying the final coats of poly. It's kind of a lot of steps, but it does work OK.

If this fails to get results on scrap, then just spray paint it.


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## deadherring (Jan 10, 2012)

Hey guys,

I ended up using gel stain and it worked out really well. By the second coat, I discovered that by really putting some elbow grease behind the wiping off and making sure I really wiped off all the excess stain, I could work the stain into the wood and get an even disribution.

I've also added the first coat of poly. The can recommends sanding 220 between coats of poly. I've never done that before so I was wondering what I am looking for when sanding in terms of when to stop? The finish seems pretty 'plasticky' right now, how far do I go before stopping? Any tips?

Thanks,

Nathan


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## bauerbach (Mar 25, 2012)

I sand to remove any nubs or other imperfections.

if its building up more than you like, Id call it quits and not apply any more coats... trying to knock it back down without burning through in spots would be a challenge.


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