# Flatbox help where mud bed crosses butt joint



## Mattsk01 (Feb 17, 2021)

I recently upgraded to a flatbox and I keep having an issue that when I am 1st coating the mud bed and run into where the butt joints meet the mud bed the corner of my flatbox catches the butt joint tape and pulls it off the drywall. What can I do to correct this. Also can you do 1st coat mud bed and butt joint on the same day. Thanks


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## Stephen0220 (Dec 11, 2020)

this is why I always tape my butts first, that way it allows a bit of drying time for the tape to stick. If you try to run your flatbox over your flats that intersect the butt tape, the butt tape will have to at least be a bit dry so it won't peel. what you can do is mud up to your intersection, then start your box past the intersection, then fill the remainder with a 10" knife and smooth with a skimming blade. I always go over my boxes with a 14" skimming blade, it makes it smooth for second coat or final sand.


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## Mjaw (Nov 24, 2020)

Stephen0220 said:


> this is why I always tape my butts first, that way it allows a bit of drying time for the tape to stick. If you try to run your flatbox over your flats that intersect the butt tape, the butt tape will have to at least be a bit dry so it won't peel. what you can do is mud up to your intersection, then start your box past the intersection, then fill the remainder with a 10" knife and smooth with a skimming blade. I always go over my boxes with a 14" skimming blade, it makes it smooth for second coat or final sand.


Always do butt joint 1st, you will snag on small jobs that dont allow for some dry time on the butts.


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