Foam based abrasives – otherwise known as sanding sponges or sanding blocks – have become a popular option for various sanding applications – and they make up some of our most popular products. However, with all the options available, it can be tough to know which will best meet your needs. In this article you’ll learn about the various sponge products Uneeda offers, their advantages, the differences and the various technical aspects that could help you choose your ideal solution. But, of course, there is no perfect, one-size-fits-all product, so at the end of the day, optimizing your sanding process comes from a balance of knowing the technical aspects of your project needs and the abrasives, as well as some amount of trial and error to find what works best for you.
Foam Density
In general, foam abrasives are made from two densities – referring to the “heaviness”/firmness or flexibility/softness of the foam. The two options are soft density, also known as “open-cell”, and hard density, or “closed-cell”. One is not better than the other, rather they are used for different applications.
Soft Density
Soft density foam, as you might guess, is more flexible and “squishy”. Open cell foam will easily fold, flex and bounce back with no issue or permanent change. This is beneficial when sanding profiles and intricate shapes, such as on crown moldings or contours on cabinet doors, as well as edge sanding. You can manipulate soft density foam to match any curve or contour you might need to, as the lightness allows the foam to recede and mold to any shape. Soft cell sponges are also great for rounded objects, such as chair or table legs, railings or newel posts, as they can be wrapped around the workpiece. One issue that sometimes occurs with some soft density sponges is “grain shed” – in which some of the abrasive grain comes off of the sponge due to the malleability of the foam. This can cause excess grain to be left behind on your surface, while also affecting the longevity of the tool. However, Uneeda’s Ekadiamond sponges, specifically, have been shown to have minimal to no grain shed, making them a high quality option for this type of sanding. Additionally, because open cell foam is so soft, when sanding by hand, you need to be careful to use even pressure with each finger, so as to get an even and consistent finish.
Hard Density
Hard density foam is made of a thicker foam substrate, which generally isn’t nearly as flexible as open-cell products. Due to the nature of foam, all sponge products have some level of “give”, however, because closed-cell products are much less pliable, they are more suited for flat surfaces, such as inner panels or rails and styles on shaker doors, rather than curved surfaces or profiles. They do have some flex and as such, they can also be used for edge sanding. The denser foam will generally give a better cut rate, since the grain will not recede into the foam nearly as much. It will also allow for a lighter cut than conventional abrasives (sanding sheets or discs), since the foam will absorb any pressure from your fingers or vibrations (from a sander). A closed-cell foam block will allow for a consistent finish, even in hand sanding applications, because it will be thick enough to avoid uneven pressure from different fingers/awkward hand positions.
Sanding Style
Uneeda’s abrasive sponges are available for two main types of sanding – hand sanding and orbital sander sanding.
Because sponges will offer a softer finish and lower cut rate than regular sandpaper, these products are typically used in finishing applications, such as preparing a piece for stain or paint, or between layers of coating to improve adherence.
Hand Sanding
Abrasive sponges are some of the most popular and effective tools for hand sanding (sanding without the use of an orbital or other power sander) applications. While sanding by hand can be tedious, sometimes it is just what is needed to get the best finish. This is especially true for pieces with complex profiles or carvings, which may be too delicate for a sander. In this case, a hand sponge or a sanding block with foam interface pad and traditional coated abrasives could be a great option to get the finish you want. Another benefit to sanding by hand is that it can be more cost effective than owning and maintaining power sanders – which would be a benefit for lower volume shops or hobbyists.
Orbital Sander
In addition to hand sanding sponges, Uneeda offers various coated foam abrasives as well as foam accessories for the orbital sander. Using a power sander, like the Ekasand Electric or Pneumatic Orbital Sanders, with foam products is a great option to speed up the sanding process in high volume shops that produce a lot of cabinet doors or other products with curved profiles. You’ll get smooth and consistent results, and a great finish. Sometimes using an orbital sander can produce swirl marks, especially a 3×4 sander that doesn’t use a random orbit pattern. However, using a foam interface pad with a conventional disc or sheet abrasive, helps to reduce the vibration, allowing the sander to glide more smoothly across the work surface and minimizing the likelihood of swirls. When done correctly, using coated foam abrasives on a sander creates a better, more consistent finish. Plus, it’s much faster than hand sanding.
The Products
Uneeda offers a variety of sanding sponges for both types of sanding – by hand and using a sander.
Products for Hand Sanding
Uneesponges
Uneeda’s first flagship hand sanding sponge line, Uneesponge, offers a variety of tools that help you finish your projects with ease and quality. The Uneesponge line is also offered in a “green” – more eco friendly version with the same configurations.
UNEESPONGE 1IN. BLOCKS
Uneesponge 1” sanding blocks are hard density foam with aluminum oxide grain on 4 sides. This block is solid, but still has some give, making it ideal for flat surfaces and edges, especially for sanding and cleaning wood, metal, plaster, plastic and fiberglass.
UNEESPONGES ½ Inch
The ½ inch Uneesponge is a soft-density foam sponge that can be folded or scrunched and bounce back with no issue. They have aluminum oxide grain on 2 sides and are perfect for sanding all types of wood and other materials. They are ideal at sanding intricate profiles and corners with little to no shedding.
UNEESPONGES 5MM PADS
The 5mm sanding sponges are a hard density foam that provides a firm, yet flexible substrate for the aluminum oxide grains. Because it is so thin, this sponge can be folded to fit into small areas, or used for flat surfaces as well.
Ekadiamond
This hand sponge is based on our conventional abrasive belt with the same name. It features a unique diamond pattern on the abrasive surface that allows for minimal loading and better dust extraction. These sponges are a soft density foam and are extremely flexible, like the ½ inch versions of both Uneesponge and Ekasilk Plus. The grit ranges are color coded and easy to pick out, once you know them. They’ll add some fun, fresh colors to your workshop! These sponges have minimal to no grain shed, meaning you’ll get a long life from each sponge and a great finish too. They have grain on both sides of the sponge – for an even longer lifespan.
Sanding block with interface pad and conventional sheet abrasive
For those who prefer conventional coated abrasives, such as our Filmtek or Ekastorm sheets, or if you need a stronger cut rate, but have contours to match, a great option is to use a our hook and loop sanding block with a soft density foam interface pad and your favorite 3×4 sheet abrasive. The advantage to this is that using a block will give you a consistent pressure, whereas using just a sheet with your fingers will get the job done, you run the risk of pressing unevenly with different fingers. This unevenness will lead to a blotchy finish, especially if using stain.
Products for Sanders
Ekasilk Plus
Using a power sander will of course speed up the process and provide more consistent results than hand sanding. Ekasilk Plus is one of Uneeda’s flagship products that comes in a wide range of formats. These sponges have a hook and loop backing and are available with or without holes for dust extraction. For rectangular sanders, they are available in both 3×4” and 3 ⅔ x 7” and for random orbitals, they are available in 3”, 5” and 6” discs. Ekasilk Plus is used primarily in finishing processes because cut rate is softer than with conventional abrasives, therefore providing an excellent option for scuff sanding and creating a gorgeously smooth surface. They are available for a variety of grits ranging from coarse through superfine – with grit equivalents of 60 grit through 450/500 grit, at the high end. No matter which sander you’re using, these sponges are available in three thicknesses – each of which is ideal for different applications.
- 5mm
- The 5mm sponge is a hard density sponge that is used for various finishing applications on flat surfaces. It provides a smooth cut and is great for applications in solid surfaces or wood, such as countertops, butcher blocks, and tabletops. These sponges in the 3×4/3 2’3×7 formats are also great if you need to sand in tight spaces, such as on a louver door or shade, because you can offset the sponge from the backup pad, and access those hard to reach areas.
- 10mm
- The 10mm sponge is also a hard density sponge. It’s great for use on flat surfaces that are slightly recessed, such as inner panels of shaker doors. The height allows you to sand up to the edge and into the corner without damaging the rails and styles. This and the 5mm are both good for sanding down edges.
- ½ in
- The ½ inch sponge is a soft-density sponge which has a lot of give. It will match any contour you have, and is great for finishing projects with complex profiles or curves, such as chair/table legs, newel posts or even cabinet doors with profiles. The grain will recede into the foam, matching all the contours and avoiding flat-spotting.
Interface Pads with conventional abrasives
An interface pad is an accessory made of hard or soft density foam with hook and loop connectors on both sides, so that one side connects to your hook and loop back up pad and a sanding sheet goes on the other side. Similarly to using a foam interface pad on a hand sanding block, this product allows you to combine the benefits of your favorite conventional abrasive, such as Filmtek or Ekastorm, with the benefits of using foam: getting a better cut rate while sanding complex areas, minimizing vibration and swirls and consistent sanding results. We offer two types – hard or soft density – depending on your needs and both options are available with or without holes for dust extraction.
Applications
Sanding sponges are very versatile tools in the sanding process. They can be used for a variety of applications on both flat and rounded surfaces, sanding in tight spots or large, spread out areas. A few of the applications where foam comes in handy are:
- Stripping
- While stripping is often done with conventional abrasives, if you have a curved surface, for example, using an interface pad with a lower grit sanding sheet – especially film – can allow you to get the cut rate you need while managing the contours on your profile. Alternatively, using a coarser grit of 10mm Ekasilk Plus can allow you to strip the inner panel on a cabinet door without harming the edges.
- Prepping for Finish & Between Coats of Finish
- The Ekasilk Plus line, as well as Ekadiamond and Uneesponges are all great options for finish sanding – whether prepping or sanding between coats of finish.
- Distressed Finish
- Both Ekasilk Plus and the 1” sanding block are great options for creating distressed finishes.
Conclusion
Sanding sponges and foam blocks are a great tool to have in your sanding arsenal. Whether you’re sanding flat or rounded surfaces, tight spaces, corners or large flat areas, these tools offer unique advantages in the finishing process. Soft density foam allows for matching contours and hard density provides a firmer option. Uneeda offers foam abrasives for both hand sanding and use on orbital sanders. If you’re looking to find your optimal sanding process for efficiency and great results, give these products a try. If you’re not sure where to start, contact a Uneeda representative to get your questions answered.
