Sky Hits Posted July 7, 2009 Share Posted July 7, 2009 Hi all, I tried an experiment and purchased a sanding block (medium fine grade) and tried it out on the back of one of my La Scalas. The good news? Under this boring mat black paint, there is wood grain underneath! The bad news? Doing it by hand would be a lot of work, effort and time. So, I'm looking for a power sander to borrow from one of my friends. Any advice or direction from any of you on this project is warmly welcome here. Here is a link to what will someday (soon!) be the "Before" pictures: http://forums.klipsch.com/forums/t/119331.aspx?PageIndex=1 Cheers, Seth Quote Link to comment Share on other sites More sharing options...
oldenough Posted July 7, 2009 Share Posted July 7, 2009 Go slowly and carefully. I just finished sanding and staining my La Scalas. Started off with 100 grit to remove the existing finish, then worked my way to 260 grit. Used a wipe on stain and two coats of eurathane to lightly seal them. I am very happy with the results, not factory perfect but very presentable. Caution is the key. All the best. Quote Link to comment Share on other sites More sharing options...
Moderators dtel Posted July 7, 2009 Moderators Share Posted July 7, 2009 What Oldenough said plus don't sand on corners, if so VERY VERY lightly. Quote Link to comment Share on other sites More sharing options...
Sky Hits Posted July 7, 2009 Author Share Posted July 7, 2009 Exactly the kind of direction I was hoping for. Thanks both. Quote Link to comment Share on other sites More sharing options...
gnatnoop Posted July 7, 2009 Share Posted July 7, 2009 Go slowly and carefully. I just finished sanding and staining my La Scalas. Started off with 100 grit to remove the existing finish, then worked my way to 260 grit. Used a wipe on stain and two coats of eurathane to lightly seal them. I am very happy with the results, not factory perfect but very presentable. Caution is the key. All the best. wonderful job old. those turned out great. Quote Link to comment Share on other sites More sharing options...
maxsdad Posted July 7, 2009 Share Posted July 7, 2009 Hi! I'm new to the forum but have made high end custom wood designs for many years. The previous advice is very sound, but let me add: 1. That woodgrain is a veneer - a very thin veneer, and what's underneath will not be as pretty. 2. A power sander is a very handy and potentially VERY destructive tool. Imagine being able to go 4000 times faster than you did by hand. Now imagine doing while you hand was numb and you can't feel what it's doing. Let just the wight of the sander do the work, and check your depth of cut constantly. I use 100 grit to radius the edges off of corners or remove large amounts of stock very quickly with a randon orbit sander. Always keep the sander moving when it is on the work, or it will dig a hole in the veneer. 3. In terms of grit number - My rule is to use the finest grit that will get the job done. Remember that you may not see them, but each grit leaves scratches that the next finer grit replace with finer scratches, and each set of those scratches is made by removing wood. Look at a cross section of veneer plywood and compare the veneer layer to the structural plies. Your skin is many times thicker! If I can't rub it on my forehead , I don't rub it on veneer. Nothing brings the gratification of seeing woodgrain come to life under your touch. enjoy! Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted July 7, 2009 Share Posted July 7, 2009 old enough very nice work. those look great. the gray horn interior gives it a clean EV look. Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted July 7, 2009 Share Posted July 7, 2009 I'm with maxsdad on the caution factor. I would not use a power sander. Even if you don't ruin the wood beyond repair, if you're not fairly skilled (and I mean that from my bad experience) you WILL wind up with a wavy surface. I would just get a big sanding block (not those little 3" x 3" blocks, but the 3" x 12" blocks) and do it by hand. Do not just sit there in one spot and grind a valley into it. Go laterally in direction to the long side of the paper. Use fairly wide strokes, like 6" to 8" strokes. Just do enough to barely break through to the clean wood, and then, start working adjacent to the clean spot with mild overlap of the clean spot. Keep working in that order and repeat as you work all the way through it. It is a job of patience, so be patient. Just allow yourself 3 evenings or so for one speaker. I don't see a big problem using the coarse grit suggested. As I recall, going finer than around 280 on wood is pointless. Wood never gets smoother than that. At least that's what I've heard, if I recall correctly. Of course that advice might not apply to a clear coat, which you could use a very fine material to buff it to a nice gloss. If you go with a power device, you might kick yourself around the block wehn you finish. How will you know you're finished? When you realize you just ruined them. Been there; done that - on bathroom cabinets. Just my 2 cents... Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted July 8, 2009 Share Posted July 8, 2009 Additionally, I advise that you regularly rub your hand lightly across the surface you are sanding, making sure your rubbing motion overlaps the sanded surface and the unsanded surface. It is better to look off in another direction as you do this. By doing so, you can monitor the progress of your sanding to make sure you are not leaving a wavy surface. I did some body work on my classic cars, and this was a must. Waviness is not visible to the eye until you put the final gloss on and realize it looks bad. So, you will have to monitor by "feel" in order to judge when you are ready to apply stain and clear coat. Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted July 8, 2009 Share Posted July 8, 2009 If you're not used to using a power sander be careful as pointed out here. I use the Norton 3X blue discs at 220 grit. I wouldn't use anything rougher than that until you get some time under the old belt. Keep the sander moving at all times and work in good light so you see what it's doing. BIGGEST TIP: stay off the corners and edges with any power sander until you get the hang of it. Nothing says amateur hour faster than unevenly rounded off edges and blunt corners. Quote Link to comment Share on other sites More sharing options...
ricktate Posted July 8, 2009 Share Posted July 8, 2009 When i did my K-Horns i used castrol super clean and a japanese wood scraper to take the paint only off. It worked fine a bit messy you could use a light stripper to i guess to get black paint off.I started off sanding much like you but not getting anywhere fast and had super clean in shop so i sprayed a little and scraped it worked real well i thought. Then i used big sanding block to keep eveything flat. I was re-veneering my speakers though so this is just an idea to try.Rick Quote Link to comment Share on other sites More sharing options...
Sky Hits Posted September 1, 2009 Author Share Posted September 1, 2009 Hello again all, This Friday my friend and I are going to do some exploratory testing with different techniques. One idea we have is using a heat gun. Another idea is using stripper. The third, based on the above suggestions would be to hand sand. Any thoughts on each of these? Thanks, Seth Quote Link to comment Share on other sites More sharing options...
Bill H. Posted September 1, 2009 Share Posted September 1, 2009 If your looking to remove the Black Paint. Try Formby's Furniture ReFinisher products. Easy to use, not castic and good results without a lot of Hassle. I agree with others, to NOT use any kind of Power sanding Equipment. Take your time, hand sand and Post Pictures when your done.................... Quote Link to comment Share on other sites More sharing options...
JohnA Posted September 1, 2009 Share Posted September 1, 2009 Start with a paint stripper and then sand them, lightly! Quote Link to comment Share on other sites More sharing options...
choctaw Posted September 10, 2009 Share Posted September 10, 2009 This is from someone who owned a cabinet shop for 25 years and did alot of finishing.(and stripping) Go with the stripping! Be sure to tape off any area that you don't want stripped and check it often that the stripper is not getting under the tape. After you have scraped off all the goo (and try to scrape with the direction of the wood grain) wash the area down with laq.thinner . You can use a stiff bristle brush for stubborn spots. DO NOT USE A WATER BASE STRIPPER. This will raise the grain and make your life hell not to mention make alot more work for you. After you have it all stripped and washed then you can sand it with some fine sandpaper. I would say # 220 grit no rougher because your dealing with maybe 1/16'' ven. Again only sand with the grain.When you finish sanding blow everything off with an air hose and then wipe the whole thing down with a tack rag. Then you can stain and finish. Don't use a water base stain or you will raise the grain again. You will get a much nicer finish if you are good with a spray gun for the finish coats. You can use a water base finish coats if you want over the stain but, I really don't like them much, and I really don't know a good finisher that does. Choctaw Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted September 11, 2009 Share Posted September 11, 2009 You can use a random orbital if you have experience working with that tool. Personally? After stripping and cleaning, I use a random orbital with 320 and then very light go-over with 400. I also don't push down on the sander. Just guide it. Change pads often. A pair of Heresy's consumes 8 pads of 220, 4 pads of 400 and 4 pads of 600. A pair of LaScalas will pretty much "consume" about 2-3 times that. Good resource for pads is www.onlineindustrialsupply.com. If you use a water based stripper, it will, as pointed out, raise the grain. That can be of help if you want a stain to show off the grain patterns. Again you have to be very careful. I would stay awy rom the water based products at least until you have some additional experience. Corners? Stay away from them with the random orbital sander; just use a block with 220 and then 400 will generally clean them up unless they were "dinged" before you got them. Everyone has great advice, but the one common "thread" is be careful, take your time! Do not get in a hurry!!! Quote Link to comment Share on other sites More sharing options...
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