# US 4,399,170 A · Method for smoothing wallboard tape joints

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- Number: US 4,399,170 A
- Document ID: US4399170A
- Status: Granted
- Kind: A
- Application number: 06/416,844
- Filed: 1982-09-13
- Granted: 1983-08-16
- Earliest claimed: 1981-02-09
- Assignees: Padco, Inc.
- Inventors: Craig R. Janssen
- Web page: https://patentgrep.com/patent/US4399170A

## CPC

- B43L 21/00: Blackboard or slate cleaning devices
- B05C 17/10: Hand tools for removing partially or for spreading or redistributing applied liquids or other fluent materials, e.g. colour touchers
- B24D 15/02: rigid; with rigidly-supported operative surface
- E04F 21/00: Implements for finishing work on buildings (for working or treating building elements of stone or stone-like material B28D)
- E04F 21/06: Implements for applying plaster, insulating material, or the like {(finishing E04F21/16)}
- E04F 21/165: for finishing joints, e.g. implements for raking or filling joints, jointers (bricklayers' tools E04G21/16; repairing, e.g. filling cracks, E04G23/02 {; wallpaper scrapers or the like B44C7/02; implements for cleaning joints A47L13/10})
- E04F 21/1652: {for smoothing and shaping joint compound to a desired contour}
- B43L: ARTICLES FOR WRITING OR DRAWING UPON; {WRITING OR DRAWING AIDS;} ACCESSORIES FOR WRITING OR DRAWING (workshop equipment for marking-out work B25H7/00; teaching hand-writing or drawing G09B11/00)
- B05C: APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (spraying apparatus, atomising apparatus, nozzles B05B; plant for applying liquids or other fluent materials to objects by electrostatic spraying B05B5/08)
- B24D: TOOLS FOR GRINDING, BUFFING OR SHARPENING (abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls B24B31/14; honing tools B24B33/08; lapping tools B24B37/11)
- E04F: FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS (windows, doors E06B)

## Abstract

A finishing tool is used to smooth tape joints of interior walls and ceilings constructed of plasterboard or drywall. The tool includes a handle, a resilient polyester foam pad, and a wettable abrasive surface of short, stiff coarse nylon fibers bonded to the resilient foam pad so that they are oriented perpendicular to the surface of the foam pad. In use, the abrasive surface is wetted, and then is moved over the surface of the tape joint to moisten the joint cement. The tool is then moved in a scrubbing-type movement to work the joint cement to a creamy consistency. The surface of the joint cement is then smoothed by stroking the tool along the length of the joint.

## Claims

### Claim 1

A method of smoothing wallboard joint compound on wallboard tape joint, the method comprising:
applying water to the joint to moisten the wallboard joint compound;
scrubbing the joint with a smoothing tool having resilient foam pad with a wettable abrasive surface bonded to one major surface to work the joint compound to a creamy consistency, wherein the wettable abrasive surface of the smoothing tool comprises a plurality of coarse, short, stiff synthetic polymer fibers oriented generally perpendicularly to the major surface of the pad and bonded to the major surface by an adhesive layer; and
smoothing the joint by stroking the creamy consistency joint compound with the smoothing tool.

### Claim 2 (depends on 1)

The method of claim 1 wherein applying water to the joint comprises:
wetting the smoothing tool with water; and
applying water carried by the smoothing tool to the joint.

### Claim 3 (depends on 1)

The method of claim 1 wherein smoothing the joint comprises stroking the joint longitudinally with the abrasive surface of the smoothing tool.

### Claim 4 (depends on 1)

The method of claim 1 wherein the fibers are nylon fibers having a length of about 0.100 inch and a thickness of about 100 Denier.