Drywall Taper Concealing Fasteners and Joints.
A drywall taper conceals the fasteners and the joints on gypsum board a few times. Once all coats are applied the wall is then ready for paint. One of several levels may be specified for a gypsum board surface. The lowest level of finish may simply require taping of wallboard joints and spotting of
heads on the surface. This is done in warehouses and other areas where appearance is normally not critical. The level of finish depends, among other things, on the number of cost compound applied to joints and fasteners
Fasteners are concealed with joint compound. Joints are reinforced with joint tape and covered with joint compound. Exterior corners are reinforced with corner bead. Other kinds of drywall trim may be used around doors windows and other openings.
A drywall taper uses drying type joint compounds for joint finishing and fastener spotting are made in both a dry powder form and a ready mix form in a three general types. Drying tape compounds provide smooth application and ample working time. A taping compound is used to embed and adhere tape to the board over the joint. A topping compound is used for second and third coats over taped joints. An all- purpose compound is used for both bedding the tape and finishing the joint. All- purpose compounds do not posses the strength or workability of two-step taping and topping compound systems.
A drywall taper also uses setting type joint compounds that are used when a faster setting time than that of drying types is desired. Drying type compounds harden through loss of water by evaporating. A drywall taper usually does not recoat the wall until the next day. Setting type compounds harden through a chemical reaction when water is added to the dry powder. Therefore they only come in dry form and not ready mixed. They are formulated in several different setting types. The faster setting type will harden within as little as twenty to thirty minutes. The slowest takes four to six hours to set up. Setting type joint compounds permit finishing in drywall materials in a single day.
Joint Reinforcing Tape
Drywall taper uses joint reinforcing tape is used to cover, strengthen, and provide crack resistance to drywall joints one type is made of high strength fiber paper. It is designed for use with joint compounds on
It has a crease along the center to make it easier for a drywall taper to install in corners. Another type is made of glass fiber mesh. It is designed to reinforce joints on veneer plaster gypsum panels. It is not recommended for use with conventional compounds for general drying joint finishing. It may be used with special high strength setting compounds. Glass fiber mesh is available with a plain back or a adhesive backing for quick application.
Drywall Taper occasionally Corner beads which is used to protect exterior corners from damage or impact. One type with solid metal flanges is widely used. Another type has flanges of expanded metal with a fine mesh. This provides excellent keying of the compound.
Corner bead is fastened through the drywall panel into the framing with nails or staples instead of using fasteners, a clinching tool which is called the Crimper is sometimes used it crimps the flange and locks the corner bead into place.
Applying Joint Compound and Tape
In cold weather a drywall taper makes sure care is taken to maintain the interior temperature at a minimum of 50 degrees for 20 hours before and during application of joint compound, and four at least four days after the application is completed.
Care should also be taken to use clean tools. Avoid contamination in the compound such as dust, dirt, paint, chips, ect.
Before the drywall taper applies compound to drywall panel, the check the surface for fasteners that not have been sufficiently put into the sheetrock they normally correct it by banging them in with a hammer. A drywall taper also looks for other conditions that may affect the finishing. The drywall taper prefills any gaps between panels of 1/4 inch or more and all V-groove joints between eased-edged panels with compound. A 24- hour drying period can be eliminated with the use of setting compounds for prefilling operations.
Embedding Joint Tape
Fill the recess formed by the tapered edges of the sheet with the specified type of joint compound. Use a joint knife. Center the tape on the joint. Lightly press it into the compound. Draw the knife along the joint with sufficient pressure to embed the tape and remove extra compound.
There should be enough compound under the tape for a proper bond, but not over 1/32 inch under the edges. Make sure there are no air bubbles under the tape. The tape edges should be tight to the compound. If you do not like the way it looks lift the tape add a little compound then embed the tape again.
After embedding a drywall taper applies a thin coat of joint compound over the tape. This helps prevent the edges from wrinkling. It also makes easier concealment of the tape with following coats. Draw the knife to bring the coat to feather the edges on both sides of the joint. Make sure there is no extra compound left on the surface.
Fasteners should be spotted immediately before or after embedding the joint tape Spotting is the application of compound to conceal fastener heads Apply enough pressure on the taping knife to fill the holes. Level the compound with panel surface. Spotting is repeated each time additional coats are applied to joints.
The first coat of compound is applied to corner beads and other metal trim when first joints are given to joints and fastener. You can use the nose of the bead as a guide when you are applying your compound. The compound is applied about 6 inches from the corner bead each coat after the first is applied about 2 inches wider than the first coat.
Allow the first coat to dry completely. This may take 24 hours or more depending on the temperature and humidity unless the setting type compound has been used Its common to use setting compounds as first coats and slower finishing types for last coats. Do a good check and if necessary sand any extra spackle to avoid interfering with the next coat of compound.
The second coat is sometimes called a fill coat. It is feathered out about 2 inches beyond all first coats approximately 7-10 inches. A Professional rarely has to sand any preparation coats. If the level of finish requires it apply a third and finishing coat of compound over all fill coats.
To be a great drywall taper it takes practice heres some info on gypsumboard.
Here is a link to my home page.