When it comes to repairing a car, not everyone is able to metal finish. In fact, very few people are.
You should always try to get as close to a metal finish as you possibly can before using filler to get the rest.
Depending on the material you’re working with, some dents may come out easier than others.
This is one of the reasons why there are many different types of body fillers.
Some fillers are for deep dents, others for light scratches and some are for certain materials.
In this article, you’ll learn everything you need to know about body filler.
I’ve spent a couple of years in the trade now and have worked with a lot of different fillers.
Over time I’ve learned which is best for each application. I’ve also learned the best car body filler overall.
Reading this article will prevent you from wasting time doing repairs with rubbish filler.
The different types of body fillers
Each body filler has a different use. They’ll tell you what they’re for on the packaging.
Body Filler/Deep Fill – This is for your first skim. Deep-fill products are higher build and can fill bigger dents.
You should always pull out as much of the repair as you can before filling it with deep fill.
Everyone has been guilty of filling a panel full of mud once or twice in their career. Try not to make it a common occurrence.
Material Types – Another variation within fillers is the type of material they’re made for.
There’s deep fill that goes on pretty much anything.
Aluminum filler which is for aluminum.
Plastic or Flexi filler that’s used on plastic bumpers and other flexible parts.
You can use fiberglass, but that’s a little more specialist. I don’t use this for a normal run-of-the-mill job.
Finishing Fillers & Glazing Putty – I’ve written an in-depth article telling you everything you need to know about glazing putties.
These are used for light & final skims to help fix any imperfections before painting. They can also be used for fixing minor dents or repairs that are pulled out 99% of the way.
Best Car Body Filler For Deep Fills
The recurring theme in this article is that any of the “leading brands” will do you just fine. If it’s U-Pol, 3M, Isopon, or Evercoat it’s almost certain to be good.
When buying a body filler for deep fills it needs to be non-sagging, have excellent filling properties, and be easy to sand.
Filler isn’t cheap nowadays so it’s also important to consider the price. If you’re doing a job for someone else you should charge sundries, if you’re a DIYer, you’re just going to have to suck it up and try to use as little as possible.
Anyway, here are the 3 body fillers I’d recommend
Evercoat Rage Ultra
For me, Evercoat Rage Ultra is the one I use almost every day.
It’s a deep filling solution that ready to rub in 10 minutes. You can also apply it over sanded OEM paint and clear (this is becoming more and more common with modern fillers).
Works On
- Steel
- Plastics
- Fiberglass
- Aluminum
- Stainless Steel
- Galvanized Steel
- Sanded OEM Paint
- Mig Braze Welds (Silicon Bronze Welds).
As you can see, it’s useable on pretty much any auto body material possible.
Evercoat suggests you can use it on hard plastics and composite plastics. You can but it’s much safer to use Flexi or plastic filler as it’s much less likely to crack.
While I’m not likely to need 6mm build from a filler. This is impressive and will be useful for those looking for a high-build filler.
The recommended maximum is 6mm sanded, so it’d be about 8mm before you rub it.
What I like most about this product is that it cures very quickly.
There aren’t many fillers that are ready to rub in under 10 minutes. This will vary based on factors such as room temperature as well as the amount of hardener used.
Evercoat claims that Rage Ultra eliminates pin holes, but, I do get some. This could be down to my prep work but I always use a clean spreader, onion board and blow the repair area before applying.
I almost always finish with dolphin glaze though so pinholes aren’t a huge issue.
The shelf life of this product is 18 months. For a lot of people, this is irrelevant. It depends on how much work you’re doing and whether you’re any good with a metal finish.
At the time of writing this article body filler is rising in price. A 128FL Oz tub is going to set you back over $100.
You may be able to get it from your local trade supply shops at a lower price if you’hotore a business.
This is priced like most of the other body fillers though. It’s how much it is, unfortunately.
Buy Evercoat Rage Ultra From Amazon.com
3M Platinum Plus Body Filler
Everyone is familiar with 3M. There’s not a product that they don’t make.
Available in a 102 Fl Oz tub, platinum plus is a premium lightweight body filler that offers great build.
It Works On:
- Steel
- Wood
- Fiberglass
- Aluminum
- Stainless Steel
- Galvanized Steel
- Mig Braze Welds (Silicon Bronze Welds).
Strangely enough, this body filler also works on wood substrates. Again, I wouldn’t recommend it on plastic and neither does 3M.
3M suggest that the maximum build is 1/4inch or 6.8mm. This is very like rage with its 6mm sanded maximum. It’s pretty unlikely that you’ll ever use that 6mm, even on your roughest days.
Unfortunately, this one dries a bit slower. You can shape this filler after 8-12 minutes but should wait 20 minutes to sand it properly.
It’s recommended to use 2% hardener, but, you can get away with using a minimum of 1.5%. It’s also said that a maximum is 2.75%, this is to prevent bleed-through and other defects.
All fillers are designed to minimize pinholes nowadays. This isn’t too bad for pinholes if you apply the filler with a little pressure. Deep fills are almost always guaranteed to have pinholes and should be followed up with a glaze.
3M Platinum Plus has a shelf life of 16 months. I don’t think I’ve ever had a can that wasn’t finished before this.
It also comes in slightly cheaper than Rage Ultra when compared on a fluid oz per $ basis.
Buy 3M Platinum Plus Body Filler From Amazon.com
Dolphin One Fill Body Filler
I use this one every so often. (whenever I’m feeling lucky).
Dolphin One Fill is a filler that’s designed for the technicians that can one skim a repair. It’s super smooth and pinhole free like dolphin glaze but offers the build of a deep fill filler.
Eliminating the need for multiple skims, this is possibly the best filler for those with efficiency in mind.
Works On:
- Steel
- Fiberglass
- Aluminum
- Original Paint
- Galvanized Steel
- Mig Braze Welds (Silicon Bronze Welds).
As long as you prep the panel properly before applying filler it will stick to anything.
Unfortunately for those that are wanting a very deep fill product, this ain’t it. Dolphin One Fill has a max fill depth of 3-5mm.
This isn’t necessarily a bad thing. If you’re managing to repair a car and send it to paint in one skim, you’re probably not caking the repair with mud. 3-5mm is more than enough.
The amount of hardener used is based upon room temperature. It’s recommended to use 3% in a 50F room and 2% in a 70F room.
After 15-20 minutes you’ll be able to sand the filler. Again this depends on room temperature and the hardener % used.
From my experience, this product is pinhole free. As long as you prep the panel properly and rub it with 120-240 grit paper, you’ll be able to send it to paint after just 1 skim.
This is the cheapest deep filling product on this list. The other added benefit is that you’ll also save on glaze, making your repair cost even less.
Buy Dolphin One Fill From Amazon.com
Best Metal Body Filler
Metal filler is used instead of normal body filler for improved longevity and corrosion resistance.
It tends to feel “harder” and is also much harder to rub. You definitely want to use low grit paper for this one (working in the P40-80 range).
Metal fillers are a little confusing as you’re not supposed to cross contaminate steel and aluminum, yet the aluminum filler is recommended to use on steel?
While I believe they have their benefits I rarely use this filler because it’s way harder to rub.
Evercoat Metal-2-Metal
There aren’t too many metal fillers on the market.
Evercoat Metal-2-Metal is the one that I’ve used in the past however it’s not something i tend to use day to day.
From reading the technical data sheet, you should use it in areas that are high stress, or where extra strength is required.
Most of the time I used it as my first skim on panel joins.
I always thought the extra corrosion protection would hopefully keep my joins rust free. The only reason I stopped was because it became tedious rubbing the tight areas by hand.
It seems to have done the job for now anyway. Time will tell.
Works On:
- Steel
- Aluminum
- Galvanized Steel
Cross contamination between metals exist.
It isn’t an issue with this filler, otherwise evercoat wouldn’t sell it. I’m assuming its because it’s not pure aluminum sheet metal.
Aluminum filler is a deep filling filler too. Metal 2 Metal has a maximum fill-depth of 6MM which is the same as the first 2 fillers mentioned in this article.
As long as you keep within the 12 drops of reactor to a golf ball size of filler, it should be ready to rub in 15 minutes.
Unfortunately you’re definitely going to need to finish with a lightweight filler or glaze. Since you’re rubbing this with 40-120 grit paper, you’ll create scratches & pinholes.
The shelf life of this is a little more relevant. Metal filler sits around forever.
You’ll probably only use it on select jobs, unless you’re in restoration work.
Unfortunately the shelf life is only 1 year. It will work beyond that, but increases the chances of defects.
On a fl oz to $ basis, aluminum filler is more expensive than normal filler. This shouldn’t come as a surprise.
That said, it’s not a huge deal if you use it for your first skim before switching up to a normal filler. You wont notice the extra cost.
I’d recommend having a tin of this in your garage. If you haven’t already, experiment with it and see if its for you. Worst case scenario you use it up and don’t rebuy metal filler ever again.
Buy Evercoat Metal 2 Metal Body Filler From Amazon.com
Best auto body glazing putty
In the past glaze and putty were used by painters to eliminate pinholes and scratches. Nowadays it’s a body filler that body technicians use worldwide.
Auto body glaze is the filler that I’d recommend for final skims and minor repairs. It completely eliminates pinholes, scratches and has enough build to fill dents at the same time.
Depending on your ability to metal finish, it could be the only filler you need.
Dolphin Glaze
Dolphin Glaze is by far my most used filler. I can’t get enough of this stuff.
After my first deep fill, I’ll switch up to using dolphin.
Sometimes I’ll not even use a deep fill, I’ll just throw dolphin on thick instead.
Another thing I’ll do is mix dolphin into a deep filling filler just take make it a little thinner and easy to apply.
This is a super flexible product and will completely change how you tackle repairs.
Works on:
- Steel
- Fiberglass
- Aluminum
- Stainless Steel
- Galvanized Steel
- Mig Braze Welds (Silicon Bronze Welds).
- Original Factory Paint
There isn’t really a maximum build on this filler. I’d say you get around 2 mm if applied in a way to maximise the fill depth.
It’s a self levelling finishing glaze so you shouldn’t be using it for the build anyway. If you want the “same” product with a bit more fill, dolphin fill is the one.
You can expect to rub dolphin in 15-20 minutes, depending on room temps and hardener %.
I mean it when I say this glaze is pinhole free. It’s become a requirement in my workplace to finish in glaze.
If a repair feels slightly wrong, put a glaze on top and rub it lightly with P180 it’ll feel completely different.
It’s super easy to rub too. U-Pol recommend starting with P180 and finishing in 240. Depending on the fill, I’ll work between 80-320.
Dolphin Glaze is also one of the longer lasting products with a shelf life of 2 years from manufacture.
The rate that I go through this filler is ridiculous. It’s pretty cheap to buy a .44l pouch, but it’s also very easy to work your way through it.
If you use a mix of all your fillers as you should, it’s not too expensive. Whereas If you try and dolphin glaze the world, you’d quickly notice where your money was going.
I’m guilty of dolphin glazing the world.
Buy Dolphin Glaze From Amazon.com
Evercoat Metal Glaze Ultra
Second best to dolphin glaze is Evercoats Metal Glaze Ultra.
As you can tell by this article Evercoat is a brand that I believe in. All of the products I’ve used from them have been great. The metal glaze is no different.
It’s a very similar product to dolphin glaze and even works out slightly cheaper too.
Works on:
- Steel
- Fiberglass
- Aluminum
- Sanded Body Filler
- Galvanized Steel
- Most Rigid to Semi-Rigid Plastics
- Cured Sanded OEM Finishes
- Cured Sanded 2K Primer Surfacer
This glaze claims that it has a 3mm maximum fill depth. I believe that, dolphin glaze is probably the same too.
It also claims to cure a lot faster than dolphin glaze with a 10-15 minute sand time. This is an area where companies can make all sorts of claims though, it’s all based on hardener % and temperatures.
Since it’s a finishing glaze it will also completely eliminate pinholes, scratches and other imperfections from your repairs.
It’s also incredibly easy to sand and self levels just like dolphin glaze too.
Evercoats metal glaze only lasts 18 month from manufacture. This isn’t a huge deal, you’ll get through the 880ml tub in no time.
On a $ per fl oz basis, the evercoat metal glaze works out slightly more economical than dolphin glaze. Neither of them require a particularly big investment.
I recommend you try out both of these glazes and make your own decision on whats best. I absolutely swear by dolphin glaze, but this one is great too.
Buy Evercoat Metal Glaze From Amazon.com
Best plastic bumper filler
It’s important that you use “flexi” filler or filler with polyester in it when repairing bumpers.
Using standard body filler will lead to your repairs cracking over time. Especially if they’re in high stress areas of the bumper.
The worst feeling is putting a bumper on at refit and cracking the filler. This is way less likely to happen when you use plastic filler.
Evercoat Poly Flex
Evercoat Poly Flex is an extremely flexible plastic glaze product.
As long as you reshape the bumper beforehand, you won’t need too much build.
It’s ideal for skim coating and spot-filling minor imperfections as well.
Works on:
- SMC
- Hard Plastics
- Flexible Plastics
- Composite Plastics
- Polyester Filler
The maximum build is 3mm sanded. Again, since you’re reshaping the bumper before filling, this is more than enough build.
It requires the standard 2% hardener and will be sandable within 20-25 minutes.
As this is a finishing glaze, there’s absolutely 0 chance of pinholes and imperfections if prepped and rubbed properly.
If you don’t repair plastic bumpers often, poly flex will survive for 18 months on the shelf. Though for a lot of body shops plastic repairs are their bread and butter.
Poly Flex is only available in an 880ml tub and will cost you somewhere between 50-100 bucks. This isn’t the cheapest, nor is it the most expensive.
The better the repair, the less filler you’re going to have to use.