If you’re new to applying Bondo, you’ll know how much of a mess you can get into.
When you’re still learning to apply filler and Bondo properly, it gets everywhere.
It gets even worse when applying glazing putty since it’s a lot thinner and runnier.
As you become more experienced, it’ll get less messy.
However, you’re still going to need to learn how to clean Bondo from your spreader and other tools.
Having to rebuy spreaders and applicators every week or two adds up.
Knowing how to get Bondo off of tools will make them last longer and save you a lot of money in the long run.
In this article, I’m going to tell you how to clean bondo off tools using 5 different tricks!
How To Clean Bondo Off Of Tools
If you’ve got Bondo on your tools and it’s already hardened, here’s how to get it off without damaging your tools.
All you need is a plastic trim tool, spreader, or a plastic blade.
Using the plastic tool, try and pick or scrape the Bondo off.
After a little bit of pressure, the Bondo should fly off.
This is because Bondo is supposed to be applied to a prepped surface.
Bondo will not stick to any surface that’s prepped incorrectly.
Don’t try this with a metal tool, especially if you’re removing hardened filler from paint or alloys.
A lot of the time, you’re better off letting the Bondo dry and then picking it off rather than removing it while it’s wet.
This works great with smaller bits of Bondo, but, it’s a lot harder if you’re trying to remove huge bits of Bondo.
Dry Paper Towels
The first and least expensive method of removing Bondo from a spreader is with a towel.
Using a shop rag, blue roll or a dry paper towel is normally enough to remove filler from a spreader.
As long as the Bondo isn’t at the “cottage cheese” stage or is getting very hard.
All you need to do is wipe the Bondo off with the towel.
After a certain point, using a paper towel is going to be very ineffective. That’s when you’d have to use one of the following methods.
Use Panel Wipe
Using panel wipe is another way to clean bondo off tools.
It’s the safest method for cleaning Bondo off tools that were left around the panel when applying filler.
If you have a bottle or container of panel wipe, wet a paper towel with the panel wipe and rub the filler off of the tool.
Admittedly it’s not the best for cleaning Bondo off of spreaders.
Using panel wipe is great when the filler is still wet, but, it doesn’t work as well when the filler starts to harden.
As long as you act quickly and don’t apply too much hardener, you’ll be able to use panel wipe to clean bondo.
You can also use panel wipe to remove bondo that isn’t hardening from a panel if you want.
Use Thinners
The best and most effective way to remove Bondo from tools is to use solvents.
Using thinners or brake/carb cleaners will dissolve the Bondo in seconds.
Thinner is the way that I clean my spreader and it works every time.
Even if the Bondo has begun to harden on the spreader.
Get a paint mixing cup, a brush and fill it with thinners and leave it on your mixing table.
Once you’re done applying filler, put the spreader in the mixing cup and soak it in thinners.
After it’s covered in thinners you can brush the filler off using a paint/sealer brush.
You can also use a shop rag or towel. You’re definitely going to need one to wipe the thinners off anyway.
Using thinners or brake cleaner is one of the more expensive methods on this list.
If you want your thinners to last longer, wipe as much Bondo off the spreader as you can before cleaning it with thinners.
Use A Blade
I’m sure that using a blade is the most common way to clean Bondo off tools.
At most of the shops I’ve been to, I’d always see someone using a blade to clean Bondo.
This is fine but it’s very inefficient and doesn’t clean the spreader 100%.
If the spreader isn’t 100% clean, then you’ll get tramlines or defects in your filler the next time you use it.
You’ll also find that you may cut into the spreader, again, this will change the way the filler goes on.
If you’re using a metal applicator, a blade isn’t going to damage it. However, if you’re using a consumable plastic spreader it definitely will.
I try my best not to have to use a blade but sometimes you need to. Especially on spreaders that have been left without cleaning.
Place the spreader in filler
Another common method I see used is to place the spreader back in the Bondo while it’s still wet.
Bondo is a thermoset and cracks when pressure is applied.
All you need to do is press the spreader into the remaining Bondo on the mixing board.
Place the side that you used to apply the Bondo into the filler and let it harden.
After it’s gone completely hard, pull the spreader off and it’ll be completely clean.
Sometimes the back side of the spreader may need cleaning but the side that you use to apply filler will be clean.
Depending on the amount of filler you put the spreader in, it could also break the spreader if it’s plastic.
Overall this is the cheapest and most cost-efficient solution. There’s no need for solvents or rags.
The problem with this method is that it requires leftover bondo.
If you manage to mix up the exact amount of Bondo you need for a repair, you’ll not be able to use this method.