6 Best Weld Through Primer Review & Complete Guide in 2022

Choosing the best weld through primer is hard because countless primers in the market work in different ways.   

A weld-through primer protects the welded metal joints from corrosion and rust. And permanently prevents the upcoming possible damage. Also, it ensures the sound health of metal in the long run. When a welder applies on the surface before welding, it turns into a liquid and embraces the metal. Thus, it prevents burn-offs during welding. 

Weld Through Primer reviews

Does weld through primer work and how good is weld thru primer: Here I am going to give answers and reviews on the top-ranked primers that using in welding process.

What is the best weld through primer in the market in 2021?

Spray MAX 3680001 1k Self Etch is the best weld through primer to prevent corrosion as per the current market trend. This red-brown primer blocks moisture and prevents recurrent corrosion from coming on the welded pieces, along with a fantastic adhesion effect. Besides, the easily adjustable spray nozzle makes the application easier. Moreover, it delivers less spatter and no burn. It gives satisfactory results that are hard to find in any other piece. 

Complete Guide for Best Weld Through Primers Reviews in 2022

Seymour 20-1675 PBE
  • Outstanding durability and promising protection.
  • Fine action against rust and scratch.
  • Low smoke level.
  • Speedy cutting.
  • The gray color perfectly goes with the metal.
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Dupli Grey EDPP108-6
  • Outstanding corrosion resistance.
  • Zinc-based coating.
  • Easy, direct, and handy application.
  • Applicable on both bare and galvanized metal.
  • The drying time is a bit long yet good.
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Weld-Thru Coating
  • Corrosion-resistant.
  • Handy to use.
  • The quickest drying time.
  • Minimum splatter possible.
  • Clean and productive result.
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U-Pol 0768 Zinc
  • Available in zinc and copper
  • High performance for rust prevention.
  • Faster drying time.
  • Low splatter level.
  • Nozzle runs well.
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Spray MAX 3680001
  • Applicable on bare metals.
  • Anti-spatter.
  • Prevents moisture.
  • Super rust resistance.
  • The valve and the nozzle work like a spray gun.
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VHT SP307 Primer
  • High performance in priming bare steel.
  • Excellent for spot repair.
  • Amazing adhesion.
  • Applicable for all modern auto bodies.
  • Applicable on plastic also.
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Top 6 Best Weld Through Primers Reviews in 2022

1. Seymour 20-1675 PBE Self Etching-Excellent Adhesion

Seymour 20-1675 PBE Professional Primer, Self Etching

This Seymour primer provides a flawless welding operation undeniably. In addition, it does not contain any harmful chemicals. They can weigh 1.3 pounds and comes in a dimension of 2.5✕2.5✕9 inches. 

Its dry film contains 86 percent pigment, and this amount ensures a smokeless welding operation. Its gray color settles on the metal easily and sands the surface as expected. This inexpensive primer works just like the description. 

250℉ heat resistance

With its 250-degree heat resistance, you will find its limit to be incredible and it is a durable primer. Thus, a good welding experience is guaranteed.

Great cutting capability

Another thing you will like about it is its fast cutting speed. Though it is a zinc-enhanced primer, its cutting speed is better than an entirely zinc-based primer. 

Less smoke 

With 86 percent zinc pigment, this primer produces less smoke and electrode wear. Thus, it is friendly for both welding and natural environments. Also, users experience no breathing issues. 

Great spray tip

Its large spray tip is easy enough to use and gives an efficient touch to the metal. In addition, users find its spray-head quite useful.  


  • Its electronic galvanic action gives continuous protection.
  • Gives better performance than zinc-based primers.
  • The spray tip is handy enough to apply directly to the metal.
  • Gray color gives a shiny look to the surface.
  • Overall, its durability is trustworthy and excellent adhesion. 
  • Excellent rust protection with effective corrosion prevention features.


  • Flow is heavy.
  • Bad for small projects.

2. Dupli-Color EDPP108-6 PK Grey Weld Through

Dupli-Color EDPP108 Weld Thru Cold Galvanizd Primer, Packaging may vary

This weld coating is specially designed for modern auto body parts and panels, providing a professional look with excellent durability. The bottle contains 12-ounce liquid and measures 8.4 x 8.3 x 5.6 inches in dimension. It comes in a case of six bottles in a package. 

This gray weld coating gives a shiny look to the metal and pretty good coverage. Its drying time is different, and it takes 30 minutes to 1 hour (maximum) to dry. It gives maximum protection against corrosion.

Handy to use and applied directly

You will find this weld coating and its spray handy to use. It gives a clean spray pattern. You can put this aerosol can in warm water for 10 minutes for greater output and use it after that. 

Professional look

This aerosol spray primer gives a professional touch to the auto body. Your old object will look like new like before when primed. 

Great durable primer

This zinc-rich coating provides excellent durability. Therefore, your primed metal is ready to use for a long time.

Direct application

Often other primers do not have the ability to prime a galvanized steel. This Dupli-Color primer is capable in this matter. You can directly apply this on a dry and bare metal or a galvanized metal and also in the inner edges. 


  • Gives a remarkable result while preventing corrosion.
  • Direct and handy application with a standard conical.
  • Applicable on both bare and galvanized metal.
  • Has great durability.
  • Gives a professional touch to the auto body.


  • Inadequate for light needs.

3. 3M Weld-Thru Coating II 

3M Weld-Thru Coating II, 05917, 12.75 oz Net Wt

A primer that keeps satisfying the users for a long time with its unique features and performance. This 3M product weighs 12.7 ounces and measures 8.7 x 5.87 x 5.87 inches. Users find it more effective than copper primers. 

This zinc-based bimetallic weld coating strengthens the metallic bond between the welded parts and panels. Also ensures the minimum comeback of the corrosion. Applying this primer with a 3M Cavity Wax Plus on a bare metal gives an excellent outcome.    

Convenient to use

3M Weld-Thru Coating II is a weldable primer that comes in a convenient aerosol spray bottle. This well-sized bottle perfectly fits in a grip. And spraying is easier.   

Double action

This zinc-based product prevents corrosion from coming both on bare metals and welded metals. That means it gives double-action before and after welding. 

The greatest time saver

This spray coating attracts buyers for its fastest application and quickest drying time. For MIG welding, the drying time is 5 minutes. And for spot welding, it takes 15 minutes to dry. 

Less weld spatter

Another exceptional weld through primer that produces less weld spatter. Because of this, you will not lose your mind when the welding ends.  


  • Intense bondage prevents corrosion from reappearing.
  • Friendly for welding, terrible for corrosion.
  • The quickest drying time is a plus.
  • Equally applicable on welded and non-welded metals.
  • A great product that helps a repair shop to keep flourishing.


  • The nozzle gets clogged.
  • A bit pricey.

4. U-Pol Products 0768 Zinc/Copper – best copper weld through primer

U-Pol Products 0768 Zinc Copper WELD#2 Weld Through Primer

Less than 1 pound in weight, U-Pol Products 0768 weld-through primer provides coverage up to 53.8 square feet and this is the best copper weld through primer. This vast coverage limit makes it a big hit for great welding. The can’s dimension is 2.76 x 2.76 x 9.65 inches. 

Its smooth exterior embraces the metal finely and gives an exquisite look. In addition, this copper-rich primer handles heat better than most zinc-based primers. Also, the copper does not corrode the metal; instead, it protects the welded panels.

Time saver

In a word, this is a time saver weld through primer. It dries pretty fast, and therefore, a speedier welding operation you will get for sure.  

Low splatter level

The good news is, you will not have to experience splatter issues while using this primer. It produces less splatter and gives an easier cleaning after welding. 

Smooth nozzle

When a nozzle gets clogged, it hinders the work. But, thanks to its clog-free nozzle, the application goes on without a problem.


  • Satisfies welders with excellent rust protection.
  • Faster drying time gives a speedier welding operation.
  • It is superconductive with a smooth exterior.
  • Low splatter level saves time when cleaning.
  • The well-running nozzle provides a smooth application.


  • The cost is high.

5. Spray MAX 3680001 1k Self Etch 

Spray MAX 3680001 1k Self Etch Weld-Thru Primer (Red Brown)

Spray MAX Self Etch is red-brown, weighs 16 ounces, and measures 8 x 2.5 x 2.5 inches in dimension. To be specific, it gains popularity because of its adjustable spray nozzle.  

This weld coating has many outstanding features that will make your welding more skillful than ever. Besides, this weldable product is applicable on bare and sanded/unsanded surfaces.      

Good resistance and adhesion

This red-brown weld through primer has not only excellent corrosion resistance but also gives good adhesion. Once sprayed, the liquid settles permanently on the surface. 

Moisture blocker and rust preventer 

This product is an expert in blocking moisture from the weld. Thus, there is no possibility of future corrosion. Moreover, compared to other primers, its rust resistance ability is a bit advanced.

Anti-spatter primer

This anti-spatter primer leaves no burn sign on the weld side. Whereas other primers leave one or two burning spots, it does not leave the tiniest burn on the surface. 

Spray gun like action

With the patented valve and adjustable nozzle, you will get a professional primer with a spray gun setup. This feature makes this primer a 2-in-1 primer.    


  • The super moisture-block system prevents recurring corrosion.
  • Works like a sealer on the old coatings.
  • Applicable on bare and sanded/unsanded surfaces.
  • The adjustable spray nozzle delivers an excellent spray.
  • Anti-spatter primer without burn issues.


  • Slightly high price.

6. VHT SP307 High-Performance Self Etch 

VHT SP307 High Performance Self-Etch Primer - 11 oz

This self-etch primer is suitable mainly for plastics, fiberglass, and aluminum. This item contains an 11-ounce fluid, weighs 14.2 ounces, and measures 2.61 x 2.61 x 7.95 inches. It performs pretty highly when priming bare steel.

Three light coats do an excellent job on difficult metals like aluminum. Its olive green color delivers a different yet catchy look to the metal. It takes 30 minutes in total to dry. 

Easy etching and priming

With this self-etch primer, you will get etching and priming at a time with a single and easy step. And this primer gains popularity because of it.  

Efficient spot repairer

If you plan to repair spots and search for a suitable primer for that, try this one. Perhaps you will not find any self etch primer that repairs spots efficiently like this. 

Supercilious adhesion

When it comes to adhesion quality, this product features supercilious adhesion. Light coats dry and settle on the metal, and do not drip away easily.  

Friendly for plastic and modern auto body

It matches the best with plastic and fiberglass surfaces. Also, you can apply it on bare and stainless steel, modern auto body parts, and panels. 


  • High performance in priming bare steel.
  • Easy etching and priming.
  • Unique spot repairing efficiency.
  • Suitable for fiberglass, plastic, and bare and stainless steel.
  • Gives a higher-level adhesion effect.


  • Unsatisfactory application.

Can you weld through Rustoleum cold galvanizing compound – or Should I use weld through primer? Weld through Primer vs Cold Galvanizing – Read about cold galvanizing spray vs weld thru primer how both use to help prevent rust and protect.

Compare the weldability, the spray characteristics and which one is the best

What does a weld through primer do? 

Weld through primers is usually applied before starting the welding process. The ground of weld through primer is to keep preventing rusting of metal joints where two pieces of metal are welded together so that it can prevent corrosion and provide permanent corrosion protection on the deeper edges of the welded pieces of metal. 

Is weld through primer waterproof?

Weld through primer is waterproof but only after 15 minutes. In the case of a topcoat, it may take 30 minutes to start showing water-resistant quality. Therefore, we can’t say they are waterproof or water-resistant as there is a condition attached to them. 

How does a weld through primer work for most metals?

  • A weld-through primer works like a protective shield for the metal. 
  • It does not let the environment react with the metal and cause damage. 
  • A weldable primer turns into a liquid and flows toward the inaccessible parts for proper surface finished welding.
  • Delivers two times more vital actions on the welded metal before and after welding.  
  • It defends rust and corrosion and makes the welded pieces super strong. 
  • Increases the productivity of the welded pieces.  

 Applying weld through primer

If you want to apply the primer by yourself, carefully follow every step to get the perfect result. Wrong application of it may worsen the metal. 

Before applying the primer:

  • Clean the metal.
  • Remove the paint/protective coating with a solvent and sand.
  • Make sure that the removing process is not harsh.
  • Clean the metal thoroughly to make sure it is fully bared and spotless. 

Now carefully apply the primer on the to-be-welded surface. You can apply it with your hand or with a spray bottle. Make sure not to leave any place without the coating. 

Once you have coated the whole metal, please wait for it to dry properly. Otherwise, the metal will not get zinc bondage. Now weld the metal according to the instruction.

After you finish welding, remove the unnecessary primer from the surface. Removing the leftover primer is a must before repainting the metal. Otherwise, it will be hard for the paint to adhere to the metal. 

Weld through primer alternative

You can use  Picklex on the areas to be welded. It can keep the metal rust-free and help promote welding. check other manufacturers’ brands.

Complete Guide:Buyer’s Guide for Weld Through Primer in 2022

Best Weld Through Primer buying guide

As the metal’s protection is related to weld through primer, you must think before buying a primer. Intelligent research before shopping can save both your metal and time. So, if buying a weld through primer is your call, let’s check out the facts that you need to know.

Primary element

Weld through primers contains zinc or copper as the primary element. Generally, zinc primer is used for protecting steel surfaces from moisture, corrosion, and rust. Copper primer eliminates corrosion formed between welded pieces. Both types of primer take 20 minutes to dry on average. 

Copper-based weld through primer is better than a zinc-based primer for some reasons. A copper primer is more rust-resistant than a zinc primer. Moreover, a zinc primer is violent to the inhalation system, whereas a copper primer is not. Copper-based products cost a bit higher. 

Therefore, consider these things when choosing between zinc and copper.   

Drying time

Drying time is another critical factor and is connected with the environment or weather. Even if you buy the outstanding primer, it may fail to dry quickly if the weather is too humid or wet. 

If a primer takes 10 minutes to dry, damp weather can make it to 1 hour. So before buying a primer, make sure you stay in a dry place. Also, find a primer that dries in the shortest time possible. The quicker the primer dries, the sooner the welding operation ends.

Price and features 

Sometimes a well-featured and expensive primer can invite damage to the metal. On the other hand, a moderately sound primer can prove itself the worth of the budget. So read the features and instructions and look at the price before buying. Reading will help you to prevent unwanted damages and improve welding efforts. 

When and Why to Use Weld Through Primer


#1. What is a weld through primer?

Weld through primer is a zinc-based product. Welders apply it to the metal surfaces before starting welding. The job of weld through primer is to protect the steel from possible corrosion. Not only that, it provides permanent rust protection of the welded steel. Though this primer is made of zinc, some primers are copper-based also. Zinc-based primers and copper-based primers are almost the same in the features.

#2. When and why use weld through primer?

It would be best if you used a weld through primer before starting welding bare metals. The job of this primer is to resist corrosion and rust. If you do not apply it before, metals will keep corroding when welded together. The environment is mainly responsible here. Thus, the strength and appearance will be poor. Using a weld coating is the most crucial for cars like Toyota because it stops the collision between welded metal pieces.  

#3. Does weld through primer work?

To protect bare metal from corrosion and rust, weld through primer is a much-needed product. Two or three coats of it can stop the metal from reacting with the environment. To be specific, a weld through primer works well when it is appropriately used. Before applying a primer, the to-be-welded piece should be free from any protective coating. 

#4. What is the difference between epoxy primer and etch primer?

An epoxy primer gives a moisture barrier according to the metal’s necessity. Etch, or self-etch primer, gives a few coatings only. Etch primer is the best suitable for poorly prepared metals, where the epoxy primer is not. Epoxy is waterproof; etch is not waterproof. As a result, etch primer causes damage or corrosion. Epoxy primer is out of this problem. 

#5. Can you weld primed steel?

Yes, you can weld primer-coated steel. But before that, you have to keep some things in your mind. While welding primed steel, be sure to check weld travel speed, voltage, and filler. Prime coated steel needs extra caution when welding. Lower voltage compared to non-coated steel, gun angles between 0 and 15 degrees are ideal for welding primed steel. And for the welding filler, E71T-1C H4, E71T-12C H4, and E71T-9C H4 flux-cored wires are the best options.  Read E71T gs vs E71T 11 flux core wire.

#6. Do I need weld-thru primer?

The requirement of weld-thru primer is not mandatory but it certainly is a helping hand when you decide to weld through. It helps giving permanent rust protection on the deeper edges of the pieces of the welded metals. Weld-thru primer will cure thoroughly before welding so that it can ensure the zinc bonds precisely to the metal. After finishing welding, it will remove any sort of weld-through primer before painting so that it can ensure the paint has properly adhered to the painted surfaces. 

#7. Can you weld through weld through primer?

You can weld through weld through primer but it is not recommended because corroding zinc forms zinc oxide that protects the steel. It is also known as sacrificial corrosion. If you want to make a quality weld then you must ensure that the weld through primer is removed from the direct weld spot and you have to make sure that it is removed before welding the joint in case of MIG welding. 

#8. Where did weld through primer come from?

Weld through primer came from a general zinc-based product that is utilized in mating surfaces before starting welding. This corroding zinc provides zinc oxide, eventually which gives protection to the steel. It is called sacrificial corrosion and this is where weld through primer came from. 

#9. Can you weld through self-etching primer?

Self-etching primer is a sole product of Eastwood and it has the combination of a benefit and a capability. Self-etching primer combines the capabilities of an old-school self-etching primer as well as the benefits of a weld through. This unique and different formula has also an organic binder that has the power to replace contributory heavy metals such as zinc and copper. They are also compatible with TIG, Arc, and MIG welding. 

#10. When to use Weld through primer on welding flanges?

Weld-through primer is used when both the GMA (MIG) welding and spot welding flange surfaces are to be protected from corrosion. When the mating surfaces must be regularly cleaned, a quality weld through primer will provide a high quality, tough coating to protect the surfaces from damage during cleaning. Weld-through primer is a coating that is applied to the metal substrate under a GMA (MIG) weld or spot weld when there is a corrosion requirement. The coating will have the tendency to serve as both a flux for the GMA (MIG) welding or spot welding and as a corrosion preventative coating.

#11. What kind of primer do I use for MIG welding?

There are several types of MIG weld-through primers from which to pick from, but it’s important to be aware of what the joint is going to be used for as that will determine the type of primer to use. If you choose a copper based weld-through primer, you can leave it over the joint after welding, but a zinc containing metal will create a rusty looking joint if left on too long. High purity zinc tends to give excellent conductivity, however, it will leave a grey matte coating.

#12. Which is the best 3M Weld thru primer?

3M Weld-Thru II is a convenient aerosol coating designed to prevent corrosion between welded metal surfaces. Featuring a zinc base that draws corrosion away from the weld, this product comes in a convenient aerosol can and provides the protection of spray paint in an easy-to-apply format.

#13. Which is better copper or zinc Weld through primer?

Which is better copper or zinc weld-thru primer? This question is always good because the answer depends on the application. Copper and zinc share similar characteristics for many welding applications, but there are some key differences. The advantage of copper over zinc is its higher conductivity and its greater durability and wider operating temperature range. Compared with copper, zinc is usually more economical and easy to use.

Coating material for edges in welding Guide

Final Thoughts

Now, this is all about the best weld through primers ranked in the market for your weld failure process. I have tried to describe each primer in the most straightforward language possible. Hope you understand all of them. 

Among all the brands mentioned above, my vote goes to 3M Weld-Thru Coating II. I find the features of this weld through primer better than others. What compels me to vote is its drying time. As a welder, I would look for a primer to give me a productive result in the shortest time. Moreover, I find the rest of the features quite useful.

I’m not saying that you must buy from my recommendation. You can buy a weld through primer which you think goes well with your preferences. But before that, never forget to conduct thorough research. 

Source: weld pool temperature-https://iopscience.iop.org/article/10.1088/0022-3727/46/47/475501#:~:text=The%20surface%20temperatures%20of%20the,of%20the%20different%20temperature%20regions.

weld puddle:http://www.airbum.com/articles/ArticleZenWelding.html

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