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Common sanding Q & A’s.

Are you sure I can do this myself?

You can do this yourself if you take advantage of the free lesson that comes with every sander rental from Pete’s—just be sure to book the lesson in advance, because we only have one training floor. 

If you can follow instructions (and if you don't keep running to consult your handy 'friends' who think they know all about hardwood floors because they sanded one five years ago) and are motivated and reasonably fit, we are quite sure you can do this yourself.

We don't promise that you will do the same job as a professional, but we can ensure that you don't cause harm to your floor or yourself. You don't need to be big or burly to do a fine sanding job!

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What does it cost? How much money will I save ?

A good rule of thumb is that it costs about $1 per square foot to do it yourself. This estimate includes machine rental charges, abrasive, finish, and assorted small tools. Hiring a professional will cost $3.50-$4 per square foot.

So, if you are refinishing a typical 450 sq. ft. living/dining area, you'll save at least $1,125 if you do it yourself. Keep in mind though, that smaller areas tend to be slightly more expensive because the cost of the sander rental is not spread over as many square feet. A single bedroom 10'x12' will cost about $180.

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How long will it take?

Three sanding passes with both the drum sander and the edger in one room of 140 sq. ft. takes the average customer, working alone, 5 hours. Allow extra time for houses that are more than 50 years old, for jobs that include multiple rooms (more rooms means more edging which takes more time) and for jobs involving heavy layers of old finishes.

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What kind of sanders do you rent?

All of our rental drum sanders are Clarke EZ-8s. They run on 110-volt house current and plug into any grounded outlet. These sanders use a sleeve or 'belt' of abrasive that slips over the sanding drum—no crimping or tightening of abrasive required. These sanders are not the 'tip-back' style you may be familiar with. The sanding mechanism of the Clarke EZ-8 is engaged with a feathering handle at the top of the machine, which gives the operator much finer control, reducing gouges and stop marks. EZ-8s are convenient because they can be broken down for transport and for hauling up and down stairs.

Our edgers are also made by Clarke, and we favor the B-2 model which has two speeds; the higher speed is more aggressive, and the gentler lower speed is used for the final pass with a fine-grit abrasive that’s great for reducing the appearance of dreaded edger swirl marks. We also rent the Clarke Super-7 edger which is a bit lighter and easier to operate. Click here for more photos and specs our machines.

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Will your machines fit in the trunk of my car?

Absolutely. The EZ-8 breaks down into two sections, the handle and the motor. The motor measures 17"x16"x24" and fits easily into a small trunk or back seat. Edgers travel in a suitcase-style box that will fit behind most seats. EZ-8s weigh about 125 lbs. and edgers weight about 40 lbs.

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Your ad says you have "professional grade abrasives;" what does that mean?

Most abrasive companies sell different 'lines' of abrasive, with the poorer quality papers generally marketed to the rental trades. This is lucrative for rental stores because you need to purchase a larger quantity of the lower quality sandpaper.
 
Other differences: lower quality abrasive belts have a paper backing that tends to stay stiff and rigid on the sander and can lead to chatter marks; professional grade abrasives are always cloth-backed and have a diagonal, wavy-line splice where the two edges are joined to form the tube. Inferior abrasives have the abrasive mineral simply glued to a backing, rather than embedding the mineral in a resin that is bonded to the backing. One sign of a high-quality resin-bond abrasive is that the belt or disc has abrasive mineral right up the edge with no chips or areas of exposed backing.

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How do I know if I have enough floor left to sand?

Full thickness strip hardwood flooring can go through 4 to 5 sandings in its lifetime. Most hardwood floors that were installed in the '20s and '30s fell into disfavor by the late '50s and were covered with carpet, effectively preserving them. If your home dates from 1880-1915, you may have greater cause for worry because some of the floors installed prior to milling standardization were 3/8" thick (and top-nailed to boot) and many of those floors are now too thin to sand. If you have doubts, take a picture of your floor and, if possible, find a place where you can check its thickness and cross-section, and bring that information into the shop with you.

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Do I really need to rent an edger? My belt sander can handle the edges…

Saying you can edge a floor with a belt sander is like saying you can dig a ditch with a trowel; sure, you can do it, but it’s going to take a very long time. Belt sanders are easy to handle, but they just don't have the power you need to match the aggression of the drum sander. It's a matter of simple math—if your belt sander weighs, say, 15 lbs. and has a sanding surface that is 4"x 8", that’s only .5 lbs. of pressure per square inch. An edger, in addition to having higher average RPMs (3200 per minute), focuses 33 lbs. onto 6 square inches, for 5.5 lbs. of pressure per square inch. And you can't make up for that lack of aggression with coarser sandpaper because most belt sander abrasive only goes down to 40grit, (you can go as low as 12grit on an edger). Still think you can do the same job with your belt sander?

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Can I sand off adhesive or backing from old linoleum? What about sanding painted floors? Should I be worried about asbestos or lead?

That leftover adhesive from old linoleum and vinyl is an absolute challenge to remove.  We recommend that you at least attempt to remove some of it before you sand, but don't bother trying adhesive remover (sanding is cheaper than that).  But it is worth finding out if it responds to really cheap solvents and the three to try are water, paint thinner and laundry detergent. Some of those old glues are waterbased and will soften or dissolve if you wet a towel and let the towel sit on the floor for 20 minutes.  Paint thinner should be used more sparingly because of its vapors, but try soaking a small area to see if it softens the offending glue layer. Laundry detergent is the substance to try if you suspect the adhesive has a grease or tar base.  Again, test a small area first to see if you can get the adhesive to soften before you flood the floor with it. If none of those solvents helps, then your best bet is to sand it off with an edger using very coarse (12 or 16grit) paper. Get about 75% of the old glue off with the edger, then you can switch to a drum sander without fear of gumming up the chassis with abrasive or accidently hitting a nail that was buried under all the gunk.  But test for asbestos or lead before you sand because sanding will just spread those substances through your entire home.

Sanding painted floors is also challenging because floor paint is thick and packed with solids.  Our best advice is to start coarse and move fast with your machines (on the coarse grits) to keep the paint as cool as possible so it doesn't melt and load up your sandpaper. Floor paint that was applied prior to 1978 could still potentially contain lead (even clear finishes like shellac and varnish contained lead prior to 1978, but paint is more likely to have it and the older it is, the higher the likelihood of lead). We sell single-use lead test sticks that are EPA approved. Sanding a lead-based finish will aerosolize the lead and spread it into your air and onto every surface in your home, putting you and especially your children at risk for lead poisoning.  When in doubt, don't sand.

Pete's Hardwood Floors is a lead-safe certified contractor and Kadee is a licensed lead assesor and can answer any questions you may have about understanding or managing the risks of sanding a lead-bearing finish in your home, just call the store!

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What do I need to do to get my floors ready to sand?

  • First of all, measure the room—it's much easier to estimate abrasive and finish needs if you know your square footage.
  • Next, remove all carpet, tack strip, carpet pad and especially the carpet staples (sanding over metal creates a spark hazard, and it can destroy the rubber drum or disc plate of a sander).
  • Remove or counter-sink any nails in the floor.
  • Remove all quarter-round; however, it's not necessary to remove the baseboards. If your quarter-round is painted to your baseboard and removing it will mean a huge repainting or replacement job, you can skip it. You’ll just have to be more careful as you edge, and use a sharp scraper to clean the floor right up to the quarter round. You'll also need to do some paint touchups on the quarter-round when you're done.
  • Remove doors that open into the room.
  • Remove all furniture—yes, all of it—and take down window treatments and wall hangings.
  • Raise and secure any low-hanging chandeliers, or you'll hit your head.
  • Fumes from oil-modified polyurethane can be lethal to small pets (birds, gerbils, guinea pigs; anything smaller than a rabbit) so we require that those animals be removed from the premises for the entire coating process. Larger pets can stay in the home, but we recommend securing them on another level to keep them away from the work area. If your pets are traumatized by strangers or noise, you might consider sending them on a short vacation until you're done.
  • Take some "before" pictures so you can remember how bad your floors looked before you started (and because we give free t-shirts to anyone who brings in their before and after photos).

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Will these black stains sand out?

This is always a hard question. It is almost impossible to tell by looking if a stain will sand out. Dark stains from urine are the worst, largely because decomposing urine is a strong alkali and discolors the wood chemically. However, it is always best to try to sand out a stain before resorting to more drastic measures; occasionally they do sand out.

If the stains don't lighten on sanding, patching is an option. Wood bleach is available, but we find that the results are so unpredictable that we aren't willing to sell it.

If you do try to bleach, do not use household bleach—buy a product specifically designed for wood floors and do it 2-3 days before sanding so that the wood has time to dry.

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Should I use stripper on the floor before I sand to save on sandpaper?

Trust us; the money you save on sandpaper by using stripper will be spent three times over on stripper and on the chiropratic work you will need after trying to strip your floor on your hands and knees. 95% on the time it is better to just sand off any existing finish from that floor - that is what all those coarse sandpaper grits are designed for.

Used wisely (which is where Pete's comes in, so ask us about how to do this) sanding off old finish will be quicker, cheaper and easier.

Check your finish for lead first, though. Lead can be present, even in clear finishes like shellac or lacquer, and these finishes should NEVER be  sanded off.

How dusty will it be?

Sanding is just not a dust-free process, and don't let anyone tell you otherwise. We strongly recommend using an attached vacuum (available for rent at Pete's) on your edger because it tends to be the weakest link in the dust-control chain. The dust bag on the EZ-8 is very efficient, as long as you empty the bag regularly.

No matter what you do, there will still be a layer of fine dust on horizontal surfaces and an even finer layer sticking to your walls. This is easily removed with a sponge and warm water. If you are sanding your kitchen, even if you do rent an attached vacuum, it is still a good idea to either pack away all food and dishware or cover the cupboards and pantry with plastic.

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We just bought a house and took out the carpet and the floors look really good—can we just buff them up a little?

First, just using a buffer to rub a dry pad or cloth over a floor will only help if you know that the finish is a fully intact, clean layer of wax.  In that case only, the friction of the buffer will melt, respread and shine up the existing wax. But this won't work for any solid finish like varnish, laquer, shellac or urethane (all of which are waaaay more likely to be under that carpet).

Now, If the finish on your floor is completely intact (no areas of wear or gray soiled patches at doorways) and you like the color, you can screen and recoat your floor (all you need to know about recoating an existing floor is right here). This means that you will sand the existing finish very lightly, just enough to create a bonding surface, and then apply one or maybe two layers of polyurethane over it.

However, this process will work only if the floor does not contain any wax residue (remember that many floors were routinely waxed in the '50s and '60s, sometimes even when they didn't need wax). Test for wax by rubbing a clean, white cloth damped with paint thinner in a corner. If a brown, waxy residue is left on the cloth, a fresh coat of finish will not bond to that floor.
 
You might also check our Photo Gallery for examples of customers who thought their floors looked okay but decided to sand anyway. The improvement in the newly refinished floor is so drastic you may change your definition of what makes an acceptable floor.

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What about radiators? Stairs?

We have specialized machines for both. Radiator edgers are designed to reach under even low radiators, though you will still need to hand scrape around legs and pipes. We also have a smaller edger for sanding stair treads. Unfortunately, there is no machine for doing the stair risers.

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Should I fill in the cracks on the floor? When?

timbermate maple for webWe limit the areas we fill to nail holes, dents, splintered board corners, and the short 'board-end' cracks. The cracks that run along the long edges of the board just aren't worth filling; boards continue to swell and shrink along that dimension and any filler will quickly be reduced to kitty litter. Trust us—uneven, cracked, loose filler looks far worse than an honest gap.
 
If you use filler, don't choose the kind that is applied after the job is done - this stays soft and comes out easily. Choose a hardening wood putty (like the Timbermate that we love - buy it here) that matches the species of wood you have and apply it before you finish sanding.

We usually sand through the 36-grit stage, fill all our holes and gaps, and have lunch; by the time lunch is over, the filler is dry and ready to sand.

Won't my finish just automatically fill in all the gaps and voids in my floor?

Sorry, but no. Floor finishes and designed to be runny so they flow level into a film. Excess will flow into the gaps between your floor boards...and straight down to your subfloor.

Don't try to put it on extra-thick, hoping it will fill up your nail holes with a neat, clear plastic plug, because it won't work, and will stay uncured and milky-looking in spots where it is applied with any thickness. Use a hardening filler as decribed above and use it sparingly. 

Read more of our rather strong opinions on woodfiller here!

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What do I do once I've sanded the floor? I thought I was just supposed to stain it…

Be careful with the word 'stain'—it's the most abused word in the wood flooring industry. Most people use it to describe any coating that goes on the wood, but when we say 'stain' we mean a product that is applied to the floor to change its color, but is translucent enough to allow the wood grain to show through. Stain alone is not a protective layer—it would scuff right off in a week! Check out our arguments against staining your floor.
 
When most people say stain, what they really mean is the process of applying a protective finish to prevent damage to the floor from wear, water and dirt. The most common protective layer is polyurethane, but penetrating finishes such as Waterlox are also growing in popularity.

All of the systems that we sell involve applying a minimum of three coats to the floor. Both waterborne and oil-modified finishes are available. Stain can be used as a base coat under polyurethane if a darker floor is desired. Stain can be used with penetrating finishes as well, but is usually mixed with the finish before application.
 
**A word of warning: Floors made from maple, birch, pine, or fir are notoriously difficult to stain evenly and well. We will actively discourage most do-it-yourselfers from attempting to stain those floors.

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Do I always need to sand between coats of finish?

It varies according to what type of finish you are applying. Penetrating finishes do not require abrasion between coats. Polyurethanes, because they build a layer of polymer over the floor, will require inter-coat abrasion at least once during the finish process.

If you have a large area, this is best done with a buffer and an abrasive screen. Small areas can be done just as effectively with a pole sander (the tool normally used for sanding drywall seams) and a small sanding screen.

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Do I always have to sand parallel to the grain?

Yes, sanding parallel to the grain significantly reduces the appearances of scratches. There is an exception to this rule, though. Check out 'The Magical Exception of Cross Cutting' in the Choosing Your Abrasive section.

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Why do I have to lift the drum before I begin my backward pass?

If you were to leave the drum on the floor as you transitioned from going forward to going backward, you would find a little stop mark at the point where you changed direction.

In order for the machine to change direction, it has to stop. If it stops, it digs. So, for that momentary change of direction, the sanding drum must be off the floor.

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Why do I have to do the floor in two sections?

The main reason is that you want to leave yourself plenty of room to maneuver the sander, especially when you're backing up and getting into position for the next pass. If you accidentally back into a wall, both you and the sander will stop dead and leave a deep gouge in the floor; if you start with your back to the wall, you leave a two-foot section (the area that you're standing on) unsanded.

And you will quickly learn that doing a forward-backward pass over anything less than four feet is extremely tedious.

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Why sand left to right?

The three wheels of the sander are positioned so that, if you move left to right, all three wheels are travelling level on already-sanded floor. This keeps the sanding cut level across the entire width of the drum. If you move right to left, the left wheel is running on unsanded floor and so is higher than the other two wheels, causing the machine to cut more aggressively on the right side.

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Do I do all my grits on the drum sander first, then switch to the edger?

The drum sander and the edger are always used ALTERNATELY. If you sand the center of your floor with 24-grit, then you will immediately edge that room with 20-grit. Sweep the floor, then change to a 36-grit belt on the drum sander, sand the main part of the floor, then edge the perimeter at 36-grit, and so on.

It will be easier to see exactly how much finish you have left to remove with the edger, which keeps the amount of edging you have to do to a minimum. You'll also get a better blend of the straight scratch from the drum machine and the curved scratch from the edger if you alternate them.

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How will I know if I have chosen the right grit to begin?

If your abrasive fills with old finish (called 'glazing' or 'loading') immediately into an initial cut, you need to switch to a coarser abrasive. Otherwise, as long as the abrasive is cleaning the wood as you expect it to, continue with it—but not forever—see below for sandpaper limits.

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How will I know when to change the abrasive?

The abrasives we sell at Pete's have very distinct lifespans; drum sander belts should last between 250 and 300 square feet each and edger discs should be changed every 20 linear feet. If your paper is loading or glazing well before the paper's scheduled expiration, that is a sign that you have started with too fine a grit for your job - throw away that loaded sandpaper and start with a fresh piece at a lower grit.

Customers often tell us that they continued to use their paper beyond its lifespan because, "it still felt sharp" or "it was still producing dust." Neither of these conditions is a trustworthy was to evaluate your abrasive. Remember that the sharper your paper, the more quickly and efficiently it cuts.  As one very wise customer recently told us: sandpaper is cheap, time is expensive.

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