

🛡️ Prime like a pro — bond stronger, cure faster, and never miss a beat!
Loctite 37509 Klean 'N Prime Anaerobic Activator is a high-performance aerosol primer designed to boost adhesion on inactive metal surfaces including plated parts and precious metals. It accelerates cure times for anaerobic adhesives even in cold environments below 41°F, making it ideal for automotive and industrial applications. Compatible with a wide range of parts and fasteners, this 4.5 oz spray ensures durable, leak-proof bonds and premium reliability trusted by professionals.









| ASIN | B0002KKTSG |
| Best Sellers Rank | #30,923 in Automotive ( See Top 100 in Automotive ) #100 in Care Corrosion & Rust Inhibitors #1,295 in Oils & Fluids |
| Brand | Loctite |
| Color | Gold |
| Date First Available | July 7, 2004 |
| Global Trade Identification Number | 00079340375093 |
| Item Form | Spray |
| Item Package Quantity | 1 |
| Item Volume | 4.5 Fluid Ounces |
| Item Weight | 6.7 ounces |
| Item model number | 37509 |
| Manufacturer | Loctite |
| Material | Silicone |
| Number of Pieces | 1 |
| Package Information | Can |
| Product Dimensions | 5.6 x 2.17 x 2.17 inches |
| Specific Uses For Product | Fleet and plant maintenance. |
| UPC | 079340375093 |
| Unit Count | 4.5 Ounce |
| Viscosity | High Viscosity |
| Viscosity Level | High |
| Water Resistance Level | Water Resistant |
M**T
Use at assembly to prevent leaks and seal. OK for break lines.
Nice sealer to prevent leaks, easy to use, works well, but you must use the activator/cleaner for it to set up.
B**Y
Good Product for Cleaning before Assembly
1st off, this product IS NOT intended to clean greasy parts from the get go. It's merely use as a final clean before assembling your parts. Note: This product contains ACETONE and BUTANE and is highly flammable. Even though Acetone and Butane is not consider extremely toxic on certain web sites, I would consider as such. Meaning, you should be in a WELL ventilated area. I did my work outside and it still can take your breath away. I would highly recommend wearing gloves (e.g. nitrate) while working with it. It will dry the moisture out of your skin. Finally, wear a face shield for eye protection too. I hung my parts [bearing race] on a wire as I sprayed them down and let them dry. It remove any residual oil film on the race. I am using Loctite 660 to glue this bearing in place, due to spinning on its own. All of this is needed to insured that the glue bonds to both metal surfaces for the bearing race. I am well pleased how my project turn out and save me an expensive repair.
J**L
Great for priming stanless steel
I have four non-tapered stainless steel pipe connections on a heating system storage tank. All attempts to seal the fittings with tape or pipe sealants failed until I primed the fittings with this product, and used Loctite thread sealant. One warning, after applying loctite thread sealer, the sealant begins setting within minutes, so if you prep the threads with this product, keep in mind that it quickly cures thread sealant. For Stainless steel pipe fittings, I highly recommend this product.
D**R
Fingers crossed, so far the "permanent" Loctite is holding fast
First, "what's inside": Acetone 67-64-1 60 - 100% 2-Ethylhexanoic acid 149-57-5 0.1 - 1% Isobutane 75-28-5 10 - 30% Basically: cleaner, catalyst, and propellant. I had a knurled grain mill roller with a right-hand-threaded drive shaft that unfortunately I wanted to run in reverse, which mean the shaft would immediately unthread. I picked up some "permanent" Loctite and this "Activator" and after first cleaning both male and female threads to within an inch of their (or my) lives I applied the "Activator" to both parts, let them sit for an hour to ensure both parts were thoroughly dry, then applied the thread locker and screwed in the drive shaft and then let the assembly sit for 24 hours. Tested the mill with a full hopper of grain (~18 pounds) and it plowed through it all with zero issues. Knock on wood :) Cheers!
I**Y
Great!
This Loctite Primer is great for instantly hardening the 401 and 406 Prism adhesives. I have used it to stiffen joints and plastics. Its really important to have this on the shelf just in case. When you spray it, don't have the container of adhesive anywhere near it. You might glue it shut!
M**C
Loctite
Works as expected
M**L
Works FAST!!!
I prepped the main shaft and fifth gear splines off my Dodge NV4500 transmission. It worked so fast, that the Loctite started to cure about 15 seconds after I applied it, causing the fifth gear to stop about halfway while sliding the gear into the main shaft. I had to use a gear pulse to remove it. Then I had to clean all the old Loctite off both surfaces before trying again. Which I did WITHOUT the Loctite Prep!Activator Spray.
Z**2
I had hoped for better results
I used this product in an attempt to fix a loose pipe connection on my air compressor and seal the leak. Unfortunately, even after using this product to prep the surface the loctite sealant did not produce a hardened loctite seal and the pipe turns under pressure. I was hoping for a more permanent connection as a final outcome.
B**R
excellent
M**C
Works exactly as described
Trustpilot
1 day ago
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