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richards
01-10-2007, 12:25 PM
I don't know whether this even belongs on the Shopbot Forum, but hopefully someone knows how to finish Alder. Using the traditional methods, sand to 150 grit, wipe down with mineral spirits, coat with sanding sealer, lightly sand, and finally top coat with polyurathane leaves lots of 'blotching' where the grain has raised. The second attempt was to sand to 150 and then spray on shellac. Blotching wasn't as bad, but still visible. Third attempt was to sand to 220 and then try shellac. Blotching was worse than the sample that was sanded to 150 grit. Fourth attempt was to sand to 150 grit and then spray with lacquer. I've just sprayed on the the 6th coat of lacquer and still haven't sealed the wood enough to get an even shine, but there is no 'blotching'. (Attempts two through four went straight from sanding to top coating without using mineral spirits or sanding sealer.)

Any ideas from those of you who regularly work with Alder?

terryd
01-10-2007, 12:45 PM
I remember now, its all coming back.....uggghhh!
I had some barstool seats to finish, 125 of them, and got a great deal on Alder so thats what we used. Did what you did and ended up using a hi build automotive primer/sealer called "Red Velvet". I'm sure the stuff was full of lead but it did work and the seats still look good after two years.

terryd
01-10-2007, 12:54 PM
Sorry Mike too quick with the enter button. To better explain Alder check out this link http://www.woodweb.com/knowledge_base/Staining_Alder.html The reason I stopped using it is because its grain often causes finishes to look like blotching and since no two pieces of lumber are the same finishing was a lottery which I often lost.

TerryD

richards
01-10-2007, 02:31 PM
Terry,
Thanks for your help. My customer wants the natural look of rustic alder, but without the blotching. As you know, the grain pattern around a knot is wild. Some areas are more like end grain, which are the areas that tend to 'blotch'. I don't mind the huge variation in coloring because that is exactly why the customer wants to use alder, but it would be nice if similar areas looked similar.

I'll try some of the suggestions in the woodweb link that you posted.

wooddr
01-10-2007, 02:52 PM
Mike,

Alder is one of the hardest woods I have worked with in the blotching area. I have a product made by Minwax called Pre-Stain wood conditioner. I haven't used it much, but an old painter friend of mine recommended this product to me and he uses it.

Good luck

Dirk Dunham

matt_r
01-10-2007, 03:50 PM
Mike,
I'll second the pre-stain conditioner. I've not used it on Alder, but have used it on Pine, and had good results. You can get it there at Home Depot.

I can come out and take a look if you like. I did 34 benches out of knotty alder for a restaurant back in October, and they turned out great.

-Matt

robert_cheal
01-11-2007, 01:09 AM
Mike,

Can your put a colored glaze over the sealer and then apply your finish coats? Glazing seems to even out the over all color. I've used light to dark glazes, most of the rustic Alder jobs you see around here are using a glaze. You might check with the formerly MHS and now Louis and Co. they provide materials for speciality finishes to all the cabinet shops.

Robert

richards
01-12-2007, 08:31 PM
After trying several suggestions, the most successful method of preventing 'blotching' seems to be using bullseye shellac diluted 2:1 with denatured alcohol. Although it prevents 'blotching', at least in limited testing, it does require light sanding before applying the top coats. Lacquer also works very well, but I don't have a spray booth, so taking a chance of blowing up the shop and house from lacquer fumes (especially in the winter with the gas furnace running 90% of the time) is too great a risk.

Using pre-stain conditioner was almost as good as the shellac, but there was still some 'blotching'.

Of course, it was totally impossible to run a completely fair and objective test. Each piece of Alder has its own characteristics, so, the pieces that I used with the pre-stain conditioner might have 'blotched' with the shellac. In a few weeks when the project is totally ready for finishing is when I'll really know whether the shellac method works best.

Many thanks to all of you who posted here on the forum and for those who emailed and telephoned with their suggestions. You're a great group!

(One thing that I have decided is that Alder will no longer be on my 'preferred' list.)