Spackle vs. Joint Compound – Differences and Uses

You may have seen the terms spackle and joint compound being used interchangeably on online DIY building forums. But are these two really the same thing? Can you use spackle in place of joint compound? We answer this and more questions in this informative blog article?

What is spackle?

Spackle- also referred to as spackling paste- is a wall-patching paste that’s commonly used to fill up minor dents and holes in plaster walls and drywall walls. This filler putty is made by mixing gypsum powder with binders. However- several other types of spackle exist that replace gypsum with other components such as vinyl, acrylic, and sodium silicate.

Spackling paste is preferred for minor wall restoration projects because it cures within 30 minutes. The fast drying time means that you can fill in dings on the wall, and still sand and stain it on the same day.

What is joint compound?

Joint compound- also known as drywall mud or sheetrock mud- is also a type of filler putty- just like spackle. This filler paste is made by mixing water and gypsum dust and its consistency can be compared to that of cake frosting. Once the drywall panels are attached to the frame of the wall, the seams between the sheets are usually taped down. However, the taping is unsightly and can’t be left uncovered. That’s where joint compound comes in; it’s mostly used to conceal seam taping so that it isn’t visible.

Spackle vs. Joint Compound – Differences

There are several similarities between spackle and drywall mud. For starters, both can cure rather fast under the proper environmental conditions. What’s more, both of these finishing pastes shrink to a certain degree once they cure. However, there are multiple differences that clearly set these two materials apart, as discussed below:

Consistency.

While both are types of wall filler paste, spackle and drywall mud have different consistencies. Joint compound is considerably denser, with plaster-like consistency. Spackling paste- on the other hand- has a rather light consistency that’s comparable to that of toothpaste.

Usage/General Purpose

Drywall mud is mainly used to finish drywall seams after the panels have been hung. Spackle- meanwhile- is most commonly used during wall repair projects. Take note that while joint compound is most commonly used on drywall, spackle can be used on both drywall, plaster walls, and even wood.

Curing Time

Joint compound takes longer to dry than spackle. Even under optimal temperature and humidity conditions- drywall mud may still take as long as 12-hours to fully cure. Spackle- on the other hand- typically dries within 30 minutes.

Shrinkage Rate

Joint compound shrinks more than spackle putty once it cures. As such, more layers have to be applied. Application of the extra layers- and the wait time for each of them to cure- tends to make projects that involve the use of drywall mud drag longer.

Cost

Going by the average cost in terms of volume, spackle is more expensive than drywall mud. A quart of spackle retails for about $15, while the same amount of joint compound goes for about eight-dollars. However, you need more of the latter to completely finish your drywall seams. By comparison, only a small amount of spackle is needed for wall repair jobs. You should- therefore- almost always expect to spend more on joint compound than on spackling paste. Joint compound is typically sold in containers ranging from one-quart to five gallons.

Ease of Use

Spackling paste is usually pre-mixed and sold in squeezable containers for easier application. Joint compound may also come pre-mixed and in a container- but is sometimes sold in powder form and you have to mix it with water by yourself to create filler paste. In addition, since spackle has a lighter consistency, you can spread it more easily over wall surfaces. Joint compound- by comparison- is thicker and harder to spread out.

Differences between Spackle and Joint Compound
Spackle	Joint Compound/ Drywall Mud
Has a tacky, toothpaste-like consistency	Has a thick, plaster-like consistency
Mainly used during wall repair projects	Mainly used during drywall installation projects
Cures within 30 minutes	Takes between 12-24 hours for each coat to cure
Slightly shrinks when dry	Shrinks more than spackle when dry
Easier to work with as it spreads easily	Harder to work with; doesn’t readily spread
Costs more per quart than drywall mud	Costs less per quart than spackling paste

Spackle uses

Spackle is generally used in wall repair projects to fill in dings and nail holes. There are several types of spackle, but these can be classified into two general categories. These are lightweight spackle and heavy spackle. Lightweight spackle is usually made of sodium silicate or vinyl- and will effectively fill in minor dents and gouges on the wall. Meanwhile- heavy spackle is made from gypsum or acrylic and is used to fill in larger/deeper wall indentations.

To effectively apply pre-made spackle filler putty during wall repair, use a putty knife to run the spackling face over the hole that needs to be filled in. Once done, remove residual paste off your putty knife as you let the spackle cure. You should let spackle dry for at least as long as recommended by the manufacturer on the product labelling. Once the spackle is dry, you can then sand the wall or paint it.

Different types of spackling paste exist, as discussed below:

Lightweight Spackling Compound

Made from a sodium silicate and glue aggregate, this patching compound is great for filling in shallow holes and narrow cracks on walls. It’s recommended for use on holes not exceeding 0.25-inches deep or one-inch wide. Lightweight spackle has many advantages- including faster cure time, less shrinkage, and a smooth finish.  

Standard Spackle

This type of wall patching compound is best for filling in larger dents and gouges on drywall as it’s easier to sand in comparison to lightweight spackle.

Vinyl Spackle

This type of patching compound is vinyl-based and arguably the best when it comes to versatility of use. You can use it for repair work on wood, plaster walls, drywall, brick walls, and even stone walls. Vinyl spackle also boasts elastic polymer construction that prevents it from crumbling after it cures, and also makes it easier to sand. It’s recommended for filling in gouges that are up to 0.75-inches deep.

Acrylic Spackling Compound

For deeper wall cracks and indentations that are one-inch deep or more, acrylic spackling compound is the most effective. This type of wall-patching compound is formulated to be flexible- thus undergoes minimal shrinkage after drying. Acrylic spackle compound can be applied to different types of wall surfaces- just like vinyl spackle.

Epoxy Spackle

The last type of spackling paste is epoxy spackle- which is formulated for use on wooden surfaces. It effectively fills in dents and other imperfections on a wide range of wooden surfaces- including pine, maple, and oak. Being as it is an oil-based filler putty, epoxy spackle has a slow cure rate, and should only be finished using oil-based paint.

Drywall mud uses

Drywall mud is typically used in finishing gypsum board seams- but some types can also be used to repair plaster walls. Once gypsum boards are hung on the wall or ceiling, the joints between the boards are usually taped down to hold the boards together. Joint compound is then applied over the tape to make them undetectable. Generally, four types of joint compound exist, as highlighted below:

All-purpose compound

This type of drywall mud is formulated to be used in both drywall installation and repair projects. These may include drywall joint finishing, texturing, and filling in cracks. Its lightweight nature makes it easy to work with, while its strong bonding capabilities make it a durable drywall finishing compound.

Topping compound

This type of joint compound is usually used as the final finishing coat on drywall tape due to its smooth consistency. It’s also easy to spread and the smooth finish makes the sanding process much easier and quicker. Topping compound is also sold in powder form- meaning you can save any unused compound and reuse it in the future.

Taping compound

Taping compound is mainly used in drywall repair projects to fill in cracks. Once taping compound cures, it becomes hard, boosting the wall’s stability and durability. It can also be used on plaster cracks due to its superior bonding strength. However, this kind of joint compound is not recommended as the final finishing coat, as it’s hard to sand due to its thickness.

Quick-setting compound

For larger cracks and holes in sheet rock boards and plaster walls, quick-setting joint compound is recommended. It has the fastest curing time that allows for application of multiple layers within the same day. If you don’t want to spend several days on your wall finishing project, quick-setting drywall mud is the way to go. Finally, its durable base coat is formulated to be resistant to cracks and mold.

Can you use spackle instead of joint compound?

While spackle and drywall mud have their fair share of similarities as wall finishing compounds, they’re not exactly interchangeable. You can use joint compound to undertake minor wall repairs if you don’t have spackling paste- but hardly ever the other way around.

Drywall mud will effectively fill in dings and nail holes on the wall, but requires lots of wait time after the application of each coating. Also note that sheetrock mud shrinks more than spackle as it cures, necessitating the application of multiple coats. Meanwhile- the only time you can effectively use spackle on drywall seams is if the drywall panels are less than 0.5-inches in thickness.