Sanding joint compound

[Jsf721]

I just finished patching a 27"x14" hole in the garage ceiling. I had to cut this section to remove/replace insulation and clean out the mess caused by a leak above. All buttoned up. Just applied the last coat of compound. I hope it will be dry enough to sand tomorrow.

I have a palm sander and I also purchased some 3m foam block with the abrasive integrated.

Can I use a palm sander (unside down) to sand the ceiling. Trying to contain the dust. The palm dander had a catch bag but not sure if it works inverted.

If the palm sander would work, What grit paper would you suggest starting with and finishing with?

Thanks.

 

[NUTTSGT]

The palm sander will probably take the compound off fast. Be prepared to clean the paper off many times. I would start with something finer than normal woodworking, 150-220 and see what it looks like.

 

[BigSteve63]

Sanding screens work the best - I usually use the medium on hand sander, but should work if cut down to fit palm sander.

 

[little d]

U want something long to sand out flat, the palm sander is more square, ya might end up with ripples. If ya want to keep the dust down they make a sanding handle that attaches to a vac.

 

[Baada]

Drywall compound sands extremely fast. Depending on how smooth you put it on with the knife 2-3 quick passes with sand paper or screen ought to do it, no power tools needed. As for dust, hold the shopvac near by and that should get most of it. Wear a dust mask since it being overhead almost no way to keep it out of your face completely.

 

[Jsf721]

Guys,

Thanks very much. I appreciate your suggestions. I will do it by hand and sadly it is not that smooth. My first time a d it was a pita working on the ceiling. I may even to one more coat. I used mesh tape already. Do I need more before a finish coat?

Thanks

The palm sander will probably take the compound off fast. Be prepared to clean the paper off many times. I would start with something finer than normal woodworking, 150-220 and see what it looks like.

Sanding screens work the best - I usually use the medium on hand sander, but should work if cut down to fit palm sander.

U want something long to sand out flat, the palm sander is more square, ya might end up with ripples. If ya want to keep the dust down they make a sanding handle that attaches to a vac.

Drywall compound sands extremely fast. Depending on how smooth you put it on with the knife 2-3 quick passes with sand paper or screen ought to do it, no power tools needed. As for dust, hold the shopvac near by and that should get most of it. Wear a dust mask since it being overhead almost no way to keep it out of your face completely.

 

[Bill Ramsey]

Keep coating (thin) and sanding until you're happy with it. Use a raking light to look at it after sanding. If it's wavy, then it'll be even more noticeable after you paint. Compound sands easily, so try to get it right now. And hand sanding with a screen on a cheap hand sanding block or pole sander works better than power sanders, because you can take long strokes and you can better control how much you're removing. No way to keep it from being messy (sorry).

 

[maddawg1952]

Try wet sanding it with a sponge that's made for it, they sell them in Home Depot with the drywall tools it works WAY better than dry sanding. http://www.drywalltips.org/sanding-tips.htm I haven't dry sanded drywall in 10 years since I learned about this method. I use warm water and a damp sponge in a circular motion and get damn near flat joints every time takes a little practice as to how much pressure to put on the sponge and when to wring the sponge out, but a boatload better than cleaning up drywall dust for weeks afterwards. The key is THIN coats and do several ,wet sanding in between each coat,getting consistently wider with each coat till you can taper them into the existing drywall nice and flat.

 

[admactanium]

It sounds like your palm sander has dust extraction. The best solution I've found for small patches is a sanding screen cut down to fit a palm sander hooked up to a shop vac. If you don't do something about the dust it'll fall all over you and make a huge mess. Compound is VERY dusty to sand.

 

[Jsf721]

Thanks guys, off to HD to get the wet sanding sponge. Seems like this little patch is taking alomst as long as a larger job!.

I appreciate the tips and suggstiuons and I am puttinn them to work. Still think I need another coat

Keep coating (thin) and sanding until you're happy with it. Use a raking light to look at it after sanding. If it's wavy, then it'll be even more noticeable after you paint. Compound sands easily, so try to get it right now. And hand sanding with a screen on a cheap hand sanding block or pole sander works better than power sanders, because you can take long strokes and you can better control how much you're removing. No way to keep it from being messy (sorry).

Try wet sanding it with a sponge that's made for it, they sell them in Home Depot with the drywall tools it works WAY better than dry sanding. http://www.drywalltips.org/sanding-tips.htm I haven't dry sanded drywall in 10 years since I learned about this method. I use warm water and a damp sponge in a circular motion and get damn near flat joints every time takes a little practice as to how much pressure to put on the sponge and when to wring the sponge out, but a boatload better than cleaning up drywall dust for weeks afterwards. The key is THIN coats and do several ,wet sanding in between each coat,getting consistently wider with each coat till you can taper them into the existing drywall nice and flat.

It sounds like your palm sander has dust extraction. The best solution I've found for small patches is a sanding screen cut down to fit a palm sander hooked up to a shop vac. If you don't do something about the dust it'll fall all over you and make a huge mess. Compound is VERY dusty to sand.

 

[maddawg1952]

DAMP!!! not a wet sponge and wring it out often, warm water works the best. Circular motion and you can see it will blend the JC in nicely.

 

[admactanium]

I'm going to try that next time maddawg.

Having re-drywalled a few rooms in my house and then later hiring out a bit of work to a handyman around town I got to see the real difference between a professional drywaller and myself. I'm not terrible at drywall myself, but the guy I hired could get to a nearly paint-ready finish just with the knives. He hardly ever sanded. The key was indeed very thin layers in increasing blade widths. I know this intellectually but it was useful to see him do it myself. I was pretty amazed honestly.

 

[srmofo]

ohhh buddy. youve got some sanding to do.

next time watch a few videos on how to mud. I did the last time I had several patches to do and I had about 5 minutes total sanding for the entire 10x12 1/2 bath/laundry room.

Granted it took me several days to do it because I was using the premade mud and it takes forever to dry. Plus I only had a short window everyday to do the work but Ill take that any day over spending hours sanding drywall mud.

 

[Jsf721]

I plan on getting another coat up before I hit the pillow tonight provided its dry. Perhaps I can get closer. I purchased a wider knife amd that may help.

ohhh buddy. youve got some sanding to do.

next time watch a few videos on how to mud. I did the last time I had several patches to do and I had about 5 minutes total sanding for the entire 10x12 1/2 bath/laundry room.

Granted it took me several days to do it because I was using the premade mud and it takes forever to dry. Plus I only had a short window everyday to do the work but Ill take that any day over spending hours sanding drywall mud.

 

[maddawg1952]

for small patches I like the pink Spackle that turns white when its dry, no guessing at when it's ready to sand or another coat. Mud in the 5 gallon pails needs to be mixed when you 1st open it too I use a mixer on my d-handle 1/2" drill and stir the living gesus out of it and sometimes even add a little water to thin it down to trowel on smoother . An old Canuck taught me that one.

 

[Tim The Tool Man]

I would advise against wet sanding. It will keep the dust down but you will never get a true surface. Use a medium/coarse 3M sanding block (80 grit) if you don't have a drywall sander and have a buddy hold a shop vac up to the area you are sanding to control the dust. You don't need to go any finer than 80 grit. You will never see the difference when primed and painted.

To speed drying aim a fan at the spot overnight...

 

[maddawg1952]

I would advise against wet sanding. It will keep the dust down but you will never get a true surface. Use a medium/coarse 3M sanding block (80 grit) if you don't have a drywall sander and have a buddy hold a shop vac up to the area you are sanding to control the dust. You don't need to go any finer than 80 grit. You will never see the difference when primed and painted.

To speed drying aim a fan at the spot overnight...

Why the advise against wet sanding? I've done whole rooms and never seen a streak in most of my apartments. And believe me It's a chitload better then sanding ceilings with a chesse grater and a vac. I'd love to own 1 of those Porter- Cable dustless sanding machines ,but $700-$800 isn't in my budget for rental units .

 

[Jsf721]

What would happen if I used a grout sponge and warm water to even it out?

 

[tcianci]

The OP seems to have violated the basic premise in finishing drywall: FIGURE, then FINISH. By looking at the picture he has posted, the correct way to approach the patch, given the surface he has now would be to dry sand the patch with a large block and 80 grit paper. It's going to be dusty, just put on a mask and your big girl ******* and get over it. The dry sanding will produce the flatness or "FIGURE" of the surface. Wet sanding with a sponge will simply follow the profile that's there and drive the poor guy nuts. Once the patch is sanded flat (BTW, if you start to see the mesh tape, you've gone as far as you can with sanding and will have to add mud and "feather" the compound back further than the original patch to get it to blend in). Once you have sanded, re-mudded and sanded flat again, then you put on a final" coat by dragging the mud hard, all you want to do at this point is take the curse off the sanding marks. When this coat is dry, then you can achieve the "FINISH" with a damp sponge. The damp sponge will melt away any tool marks and scuffs but it should not change the profile of the patch. Prime and paint, declare victory and go home proud.

 

[slghmmr88]

I just finished patching a 27"x14" hole in the garage ceiling. I had to cut this section to remove/replace insulation and clean out the mess caused by a leak above. All buttoned up. Just applied the last coat of compound. I hope it will be dry enough to sand tomorrow.

I have a palm sander and I also purchased some 3m foam block with the abrasive integrated.

Can I use a palm sander (unside down) to sand the ceiling. Trying to contain the dust. The palm dander had a catch bag but not sure if it works inverted.

If the palm sander would work, What grit paper would you suggest starting with and finishing with?

Thanks.

I have a porter cable random orbital palm sander 5 hole and use 5 hole hook and loop with my shop-vac and the small hose hookup in place of the dust bag. Works great for me and been using it for quite a few years as a matter of fact I am on my third hook and loop pad from wearing out the hooks till even a new sand disc just slings right off.

 

[where2]

I have the hand sanding screen with the water bath dust collection system that attaches to a shop-vac. It is about as dustless as you can get sanding joint compond unless you are a pro.

 

[maddawg1952]

What would happen if I used a grout sponge and warm water to even it out?

I dunno I never tried that. The sponge I used has a sponge side and a sort of textured side for taking down high spots and its a real tight celled sponge so there really isn't much of a water drip. there like $4 or so at HD.

 

[egdede]

Use a stiff 3" (or wider) putty knife to break rough **** in picture off before either re-coating or sanding.

Always apply compound in one direction so you can scrape the streaks off easy in one swipe. Wet sanding is great. A wide knife especially on final keeps things smooth enough. With thin one direction application you real only feathering the edges.

 

[Jsf721]

Guys,

Thanks very much for the guidance and suggestions. The wider knives was an awesome tip. Makes sense, wider knife-less ridges per sweep. I was using a putty knife prior and that was obviously wrong too for the job.

I am very happy with the progress I made and what I learned going this patch. I used a grout sponge with a bucket of very warm water to remove alot of the existing imperfections. After that was dry I applied a very thin coat and when that dries I hope to be ready for a light sand and paint.

I took a picture but for whatever reason Photobucket won't let me log on from work.

Will update later. Have a good week and thanks again.

Use a stiff 3" (or wider) putty knife to break rough **** in picture off before either re-coating or sanding.

Always apply compound in one direction so you can scrape the streaks off easy in one swipe. Wet sanding is great. A wide knife especially on final keeps things smooth enough. With thin one direction application you real only feathering the edges.

I dunno I never tried that. The sponge I used has a sponge side and a sort of textured side for taking down high spots and its a real tight celled sponge so there really isn't much of a water drip. there like $4 or so at HD.

I have the hand sanding screen with the water bath dust collection system that attaches to a shop-vac. It is about as dustless as you can get sanding joint compond unless you are a pro.

DAMP!!! not a wet sponge and wring it out often, warm water works the best. Circular motion and you can see it will blend the JC in nicely.

I'm going to try that next time maddawg.

Having re-drywalled a few rooms in my house and then later hiring out a bit of work to a handyman around town I got to see the real difference between a professional drywaller and myself. I'm not terrible at drywall myself, but the guy I hired could get to a nearly paint-ready finish just with the knives. He hardly ever sanded. The key was indeed very thin layers in increasing blade widths. I know this intellectually but it was useful to see him do it myself. I was pretty amazed honestly.

ohhh buddy. youve got some sanding to do.

next time watch a few videos on how to mud. I did the last time I had several patches to do and I had about 5 minutes total sanding for the entire 10x12 1/2 bath/laundry room.

Granted it took me several days to do it because I was using the premade mud and it takes forever to dry. Plus I only had a short window everyday to do the work but Ill take that any day over spending hours sanding drywall mud.

for small patches I like the pink Spackle that turns white when its dry, no guessing at when it's ready to sand or another coat. Mud in the 5 gallon pails needs to be mixed when you 1st open it too I use a mixer on my d-handle 1/2" drill and stir the living gesus out of it and sometimes even add a little water to thin it down to trowel on smoother . An old Canuck taught me that one.

I would advise against wet sanding. It will keep the dust down but you will never get a true surface. Use a medium/coarse 3M sanding block (80 grit) if you don't have a drywall sander and have a buddy hold a shop vac up to the area you are sanding to control the dust. You don't need to go any finer than 80 grit. You will never see the difference when primed and painted.

To speed drying aim a fan at the spot overnight...

Why the advise against wet sanding? I've done whole rooms and never seen a streak in most of my apartments. And believe me It's a chitload better then sanding ceilings with a chesse grater and a vac. I'd love to own 1 of those Porter- Cable dustless sanding machines ,but $700-$800 isn't in my budget for rental units .

The OP seems to have violated the basic premise in finishing drywall: FIGURE, then FINISH. By looking at the picture he has posted, the correct way to approach the patch, given the surface he has now would be to dry sand the patch with a large block and 80 grit paper. It's going to be dusty, just put on a mask and your big girl ******* and get over it. The dry sanding will produce the flatness or "FIGURE" of the surface. Wet sanding with a sponge will simply follow the profile that's there and drive the poor guy nuts. Once the patch is sanded flat (BTW, if you start to see the mesh tape, you've gone as far as you can with sanding and will have to add mud and "feather" the compound back further than the original patch to get it to blend in). Once you have sanded, re-mudded and sanded flat again, then you put on a final" coat by dragging the mud hard, all you want to do at this point is take the curse off the sanding marks. When this coat is dry, then you can achieve the "FINISH" with a damp sponge. The damp sponge will melt away any tool marks and scuffs but it should not change the profile of the patch. Prime and paint, declare victory and go home proud.

I have a porter cable random orbital palm sander 5 hole and use 5 hole hook and loop with my shop-vac and the small hose hookup in place of the dust bag. Works great for me and been using it for quite a few years as a matter of fact I am on my third hook and loop pad from wearing out the hooks till even a new sand disc just slings right off.