It's gonna gum up sandpaper! They do make sandpaper with a zinc oxide lubricant for gummy sanding. Works if you can get it and it doesn't get sunburned.
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Wet sanding raises the wood grain. But if everything is well sealed it works.
Blow off dust? We should talk about what you want to breath in. Use a real tack cloth!
Then let's talk about down draft tables and using a dust collecting sander!
All of my finish sanders have holes in the pad that connects to a dust collector. The plates to punch the holes are attached right above my sandpaper drawer. The drawer is a bit unusual as it has built into the front shelves to hold the sandpaper and then the back part holds sandpaper belts etc. and the small finish sanders. One other trick to mention is to put two sheets of thin sandpaper on at a time and when the first wears out, just tear it off and keep working! Works best on the older hard to load types.
A downdraft table is a piece of pegboard with some bracing over a sealed box the feeds the shop vacuum system.
I sand at one end of my shop and the paint booth is at the other end.
All of my finish sanders have holes in the pad that connects to a dust collector. The plates to punch the holes are attached right above my sandpaper drawer. The drawer is a bit unusual as it has built into the front shelves to hold the sandpaper and then the back part holds sandpaper belts etc. and the small finish sanders. One other trick to mention is to put two sheets of thin sandpaper on at a time and when the first wears out, just tear it off and keep working! Works best on the older hard to load types.
A downdraft table is a piece of pegboard with some bracing over a sealed box the feeds the shop vacuum system.
I sand at one end of my shop and the paint booth is at the other end.
Yes and eye protection. Not long ago I paid the price and got a bit of wood or something in my eye. I gave my self a bad eye infection(has a big name I've forgot) and could barely get to sleep only to wake up in the morning unable to look at any light, which made the trip to the hospital interesting as I couldn't look at any car headlights(Mum drove me). I also a while ago wasn't wearing a mask and sanding mdf and pretty sure I breathed it in and it felt like I had as a cold without the 'runny' nose for a couple of dayd
Please if you don't wear a mask/ eye protection wear it.
Please if you don't wear a mask/ eye protection wear it.
I am afraid I must argue against eye protection, dust protection or even wearing hearing protection! I've seen so many arguments on this site based on miscommunication, arrogance, and general nonsense that I can strongly recommend to those folks not to use any simple low cost protective gear.
Oh and I should add if you get ear plugs never clean them. If you get an ear infection from the dirt that accumulates don't worry you will get over it in a few days. Don't even think of wasting the emergency doctor's time, those tales of loosing ones hearing in a single day from an ear infection are just anecdotal. No one has ever done a double blind test to see how long it takes to lose your hearing from ear infections.
Don't waste your money on any hearing protection even the ones with the anti-microbial silver particles in the foam.
Oh and I should add if you get ear plugs never clean them. If you get an ear infection from the dirt that accumulates don't worry you will get over it in a few days. Don't even think of wasting the emergency doctor's time, those tales of loosing ones hearing in a single day from an ear infection are just anecdotal. No one has ever done a double blind test to see how long it takes to lose your hearing from ear infections.
Don't waste your money on any hearing protection even the ones with the anti-microbial silver particles in the foam.
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tack cloths are a no-no under water borne finish.
As far as dust goes I wear a mask more of the work day then I don't. also working upstream from a fan blowing out a window works to keep me out of the cloud.....
and yes I wear prescription safety glasses in the shop.They have the marks in them to tell me I need them....
and ear protection....ear plugs if I'm running machines for an extended period, or ear muffs for short runs.
Personally i prefer to use some, we are hi-fi enthusiasts after all!
Another benefit of hearing protection is it helps me concentrate on what i'm doing, not rushing to turn the tool off.
Had a look at my curvy chang cabinets, 5 years old approx, spent last 2 years in the garage, edges all sealed with dry rot sealer, and painted, no cracks so far. In fact looking at the quality of the edges I am now kicking myself for not using it on my current project. The MDF edges looked perfect till I put the paint on them, had used a cellulose based sanding sealer.
Hiding the seam is the hardest
I tested watered down pva, shellac, Laquer, BIN sealer, and Drywall compound. The problem is that the face of MDF has a paper finish, and the exposed cut edge is raw fibers. It's very time-consuming to make the edge match the face. I sealed the edge with Laquer, then kept adding coats and sanding with fine sandpaper. Drywall mud is fine after the first sealer coat, but no easier to work with.
The most frustrating thing for me was hiding the seam. I finally gave up and went with a 'hammered' finish paint to camoflage the seams. Looks ok, but I'd go nuts trying to get a full gloss shine on MDF.
You can easily see the seam around the top of the Cyberg's Needle in the picture.
I tested watered down pva, shellac, Laquer, BIN sealer, and Drywall compound. The problem is that the face of MDF has a paper finish, and the exposed cut edge is raw fibers. It's very time-consuming to make the edge match the face. I sealed the edge with Laquer, then kept adding coats and sanding with fine sandpaper. Drywall mud is fine after the first sealer coat, but no easier to work with.
The most frustrating thing for me was hiding the seam. I finally gave up and went with a 'hammered' finish paint to camoflage the seams. Looks ok, but I'd go nuts trying to get a full gloss shine on MDF.
You can easily see the seam around the top of the Cyberg's Needle in the picture.
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My only goal was to prevent oxidation and penetration of hand oil so I used a gallon of Thompson's Water Seal on (2) 40 liter 1 inch MDF cabs. It penetrates immediately and turns dark. It smells for 3 days. After that, the color fades and so far no hand prints are evident after a lot of adjustment.
The stuff I read here said: seal, prime, finish.
So far so good.
p
My only goal was to prevent oxidation and penetration of hand oil so I used a gallon of Thompson's Water Seal on (2) 40 liter 1 inch MDF cabs. It penetrates immediately and turns dark. It smells for 3 days. After that, the color fades and so far no hand prints are evident after a lot of adjustment.
The stuff I read here said: seal, prime, finish.
So far so good.
p
Seam is the glue joint
I did make them. The seam you see just above the driver is where the top is glued on. I'm not a fan of exposed end-grain. I normally make make miters, or veneer the edge. These were just an experiment to see what full-range speakers sound like (as opposed to 2-ways with a crossover). I dressed them up as far as possible so they'd look good in my daughter's room.
If I ever use MDF again, I'll plan on covering them in veneer. The expense would be much greater, but I just can't get a fine enough finish with raw MDF
I did make them. The seam you see just above the driver is where the top is glued on. I'm not a fan of exposed end-grain. I normally make make miters, or veneer the edge. These were just an experiment to see what full-range speakers sound like (as opposed to 2-ways with a crossover). I dressed them up as far as possible so they'd look good in my daughter's room.
If I ever use MDF again, I'll plan on covering them in veneer. The expense would be much greater, but I just can't get a fine enough finish with raw MDF
With the issue with small imperfections and the join seams between the mdf has any one tried something like Polycell basecoat or say a Polyfilla. The basecoat especially may also be viscous enough to seal the edges. It may be the solution depending on how smooth it goes on, but you can always give it a quick sand if it does the job.
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