How To Second Coat Plasterboard Joins
General Information 2nd Coating Plasterboard Joins
- THE SECOND COAT IS TO FILL THE JOIN LEVEL.
- DO NOT over fill the join.
- Butt joints are treated different
- Scrape back taping coat before applying second coat.
- Mix should be slightly stiffer than taping coat.
- DO NOT second coat INTERNAL CORNERS.
- Mix less material for second coat.
- Use an 8" joint knife for recessed joins.
- Use a 10" joint knife for externals and butt joints
- Use a 12" joint knife to check the joint is flat or slightly under filled.
- Scrape back excess once plaster has set.
2nd Coating Recessed Plasterboard Joins
Apply an even but full coat of mud with using the full width of an
8 inch joint knife.
Note that the joint knife is angled slightly upward. This will prevent
the mud spreading below the join.
Feather out the edge and cut off excess mud by applying pressure to
the top edge of the joint knife.
Repeat the feathering out on the bottom edge.
Finish off with two or three runs through the join with the joint knife
held flatter and square to the join.
Once the 2nd coat has set, use a 12 inch joint knife to check that the join is not over filled. If you find that you have over filled the joint, this is the time to scrape it back flat.
If the join is under filled, the top coat will fill it up level. Top coat will not fix an over filled join. Scraping it back before it dries is the only way to fix it.Go straight to top coat    Go back to taping joins   Back To Top
2nd Coating Plasterboard Butt Joins
When second coating butt joins, care must be taken not to over fill the center of the join. This will create unsightly joins. The idea is to blend the taped area into the surrounding board, over filling the tape just makes this harder.
Using a 10" joint knife apply a coat over the center of the join but cut it back with a lot of pressure to apply the minimum amount of material. Don't feather out any edges at this stage, as the edge left is our guide to how much we need to fill out from the center of the join.
Fill out from the center the full width of the 10" joint knife on both sides, again not applying any more material to the center of the join, we do not want to create a build up of material in the center. Feather out the outer edges and when set scrape back any excess material.