Popular Woodworking 2001-02 № 120, страница 22
liquid. Animal hide glue has the unique characteristic of dissolving quickly in hot water. Because hot hide glue is both hot and wet, it dissolves old hide glue when applied over it, and a strong bond to the wood is usually achieved without the old glue having to be removed first. The great advantage of continuing to use hide glue in joints glued originally with hide glue is that regluing is fast and very effective. When hide glue was the only glue available, everyone used it, and this is surely a primary reason that so much very old furniture has survived so long. Most of the old-furniture joint problems you see today are the result of one of the three lesser-quality regluing methods (discussed above) having been used. The product called "Liquid Hide Glue" is the same as hot hide glue, except for added preservatives (to keep the glue from rotting for about a year) and gel depressants (to keep the glue liquid at room temperature). It can be used fairly effectively in place of hot hide glue as long as it is first heated to about 140 degrees. Cleaning Joints An even better practice than using hot hide glue over old hide glue is to clean all the old glue out of the joints before applying new glue. The strongest bonds are achieved when the wood is totally clean. This was the condition that existed when the joints were first glued. Once the wood is clean, any glue can be applied, and the result will be strong, long-lasting bonds. The only rationale for using hide glue at this point rather than another glue is that the joints will be easier to reglue next time. There are two ways to clean old glue off of wood: dissolve it off, or scrape or sand it off. Dissolving is the better method by far, because it's totally effective and doesn't change the dimensions of the parts. Because the old glue has penetrated somewhat into the wood, it's not possible to scrape or sand off all the glue without also removing some of the wood, and this creates air spaces in the joints. Tight wood-to-wood contact, which is necessary for a strong bond, is lost. Hide glue is the easiest glue to dissolve and wash off. White and yellow glues are next. Each of these glues dissolve or break down in hot water or vinegar. Epoxy, urea-formaldehyde (plastic-resin), cyanoacry-late and polyurethane glues have to be scraped or sanded off because they can't be dissolved. Not all furniture is deserving of the time it takes to reglue with one of the better methods, but all better quality furniture is. PW Bob Flexner is a nationally known finishing expert in Norman, Oklahoma. Each of the better methods of regluing is shown on his videotape "Repairing Furniture With Bob Flexner." Send $19.95 to Bob Flexner, P.O. Box 214, Norman, OK 73070. Circle #107 on Resource Directory Coupon HOW TO REMOVE STUBBORN DOWELS To remove an old dowel that won't budge even with a pair of pliers, first saw off the dowel just above flush. Then drill out the center of the dowel using a brad-point drill bit '/is" smaller in diameter than the diameter of the dowel.The brad point helps maintain center as you're drilling; the smaller bit reduces the risk of changing the location of the hole. Use a 'A" inch chisel or other sharp, narrow tool to pick away the remaining cylindrical part of the dowel.Then clean any remaining dowel or glue from the hole with the correct-size twist drill bit or a needle-nose rasp. Can you move several thousand pounds of shop machines alone? I have the typical garage problem: cars, lawn mower, garden tools, bikes, kids toys, etc. and not enough space to share with my heavy shop machines. When I mobilized my shop machines and workbench, I created the space I needed to do my projects without sacrificing family storage space. Have the freedom to move your machines, create an organized, safe and spacious work area, and allow for additional machines with easy shop cleanup. You can, with a mobile base from HTC. Call toll-free, 1-800-624-2027 for your nearest dealer and FREE, full color Shop Solutions Catalog. HTC Products Inc. P.O. Box 839 Royal Oak, MI 48068-0839 ©HTC Products, Inc. 2000 |
