Pacer RX-50 Range Extended Cyanoacrylate Adhesive (30-70 cP)

Pacer RX-50 cyanoacrylate adhesive is a virtually non-surface-sensitive instant adhesive that runs 30 to 70 cP and fills to .004 in. It is the thinnest Range Extended grade Pacer currently offers, which makes it the pick when you have close-fitting parts and a surface that a conventional cyanoacrylate will not cure on. Porous substrates, acidic substrates, plated parts, and surfaces carrying silicone grease, oil, or release agent are all cases where a standard CA cures slowly or never grabs. RX-50 bonds them, and it fails the substrate before the bond on ABS, rigid PVC, nylon, polycarbonate, SBR, and EPDM. It meets MIL-A-46050C Type II, Class 1 and A-A-3097 Type II, Class 1, and is offered in a 20 gram bottle.

Key Product Details

Full property data for every grade in the series is in the Pacer RX Series technical data sheet (PDF). The data sheet covers grades beyond what we currently stock. Chemical Concepts carries RX-50, RX-100, RX-500, RX-700, and the RX Gel.

Shear Strength by Substrate

Tested per ASTM D-1002. Where the table reads substrate failure, the part broke before the bond did.

Diagnosing a Failed Cyanoacrylate Bond

Before you change adhesives, work out which of three things went wrong. A surface problem, a gap problem, and a cure problem all look like a joint that came apart, and each needs a different answer. Switching to a Range Extended grade only fixes the first one.

• Bonds some parts and not others from the same batch. That’s a surface problem. Something on the part is inconsistent: plating coverage, residual mold release, cutting oil, a surface treatment. A Range Extended grade like RX-50 is the fix.
• Never bonds this particular substrate, but works fine on others. Also a surface problem, and a consistent one. Common culprits are plated parts, silicone-lubricated components, and acidic surface treatments. Again a Range Extended grade.
• Cures at the edges, stays wet in the middle. That’s a gap problem. The joint is wider than the grade can bridge, so surface moisture never reaches the center. Step up a viscosity rather than changing chemistry: RX-100 at .005 in, RX-500 at .008 in, RX-700 at .010 in, or the RX Gel at .020 in.
• Adhesive ends up somewhere other than the joint. That’s an orientation problem, not a chemistry one. Any liquid grade runs on a vertical or overhead face during the 1 to 5 minutes it needs to fixture. Fixture the part flat or use the RX Gel, the only grade rated non-sag.
• Joint holds then fails in service under load. That’s a joint design problem. Cured cyanoacrylate is rigid and brittle, so it does not tolerate peel or repeated flexing. Check the bond area against the published shear figure, and ask us about Pacer’s HP Series if the joint sees real peel.
• Whole batch of adhesive behaves differently than it used to. Check age and storage. Shelf life is one year stored per the data sheet, and a cyanoacrylate past its life thickens noticeably.
• Whatever the diagnosis, test on your actual parts in the actual orientation before committing a process. A bench test on clean coupons tells you very little about a plated part on a wall.

RX-50 or E-40? Same Viscosity, Different Job

RX-50 and Pacer’s general purpose E-40 run identical viscosity at 30 to 70 cP, identical .004 in gap capability, and the same MIL-A-46050C Type II, Class 1 rating. They are not interchangeable, and the published numbers make the choice clear.

On clean steel and aluminum, E-40 is the stronger adhesive and it is the one to use. On EPDM, SBR, polycarbonate, or anything plated, oily, or mold-released, RX-50 bonds where E-40 will not, and the strength numbers stop mattering because the alternative is a joint that fails. Diagnose the surface first, then pick.

Choosing a Viscosity in the RX Series

Every grade in the RX Series runs the same non-surface-sensitive ethyl hybrid cyanoacrylate chemistry, the same -65F to +180F cured range, and the same shear strength figures except the gel. Viscosity and gap are what change.

RX-50 is the thinnest Range Extended grade currently offered. RX-5, the water-thin 2 to 10 cP grade that wicked into closed joints, has been discontinued, and there is no non-surface-sensitive wicking grade in the current Pacer line. If you were using RX-5, RX-50 is the closest match on chemistry but it will not wick, so it goes on before you close the joint rather than after. Call us if you need a wicking grade for a difficult surface and we’ll look at other manufacturers.

Performance in Production

• Bonds through silicone greases, oils, and release agents, and onto plated parts. That’s the reason to specify it, and it’s a documented property rather than a technique claim.
• Handles acidic substrates that inhibit a conventional cyanoacrylate, which is the usual cause of a bond that works on some parts and not others.
• At 30 to 70 cP it is the thinnest RX grade, so it flows into a close-fitting joint that a thicker Range Extended grade would hold open.
• .004 in gap capability means fit-up needs to be reasonably good. This is the grade for well-made parts with a bad surface, not for loose parts.
• Substrate failure on ABS, rigid PVC, nylon, polycarbonate, SBR, and EPDM. On all six your joint strength is set by the part, not the adhesive.
• 1400 psi on copper, a figure the general purpose E Series data sheet does not publish at all.
• Cuts surface preparation. Degrease, abrade, and prime steps that exist only to make a standard CA work can often come out of the process.
• Fixture in 1 to 5 minutes and 80% of strength in 15 to 30 minutes, the same across every grade in the RX Series.
• At 30 to 70 cP it is a low viscosity liquid. It will run on a vertical or overhead face before it cures, and it migrates along seams. Fixture flat and keep it clear of threads and cosmetic faces.
• Offered in a 20 gram bottle only, sold in case quantity of 10. If you need Range Extended chemistry at production volume, RX-100 and RX-500 come in a 1 lb bottle.

Common Applications

• Close-fitting parts with a plated, oily, or mold-released surface
• Bonding plated fittings and hardware
• Surfaces carrying silicone grease, oil, or release agent
• EPDM and SBR rubber, gaskets, and seals
• Acidic substrates that inhibit standard cyanoacrylate cure
• Polycarbonate and nylon assemblies
• Copper and brass fittings
• Troubleshooting an intermittent bond failure on well-made parts
• Work calling out MIL-A-46050C Type II, Class 1 or A-A-3097 Type II, Class 1

Available Sizes

The 20 gram bottle is sold in case quantity of 10 and is the only size offered in RX-50. Call us if you need a single bottle to trial on a problem part. For Range Extended chemistry in a 1 lb bulk bottle, RX-100 and RX-500 are the two grades available that way.

Related Products

• Pacer RX-100 Range Extended (80-120 cP), the broad use RX grade at .005 in gap, and the thinnest available in a 1 lb bottle
• Pacer RX-500 Range Extended, .008 in gap, 20 gram and 1 lb
• Pacer RX-700 Range Extended (600-800 cP), .010 in gap for uneven surfaces
• Pacer RX Gel, non-sag non-running gel for vertical applications, .020 in gap
• Pacer E-40 Instant Adhesive (30-70 cP), the general purpose grade at the same viscosity and gap, stronger on clean metal
• Pacer Premium Acetone Accelerator, speeds full cure through larger gaps
• All cyanoacrylate instant adhesives

Frequently Asked Questions

What is Pacer RX-50 used for?

Pacer RX-50 is used for bonding close-fitting parts whose surfaces a standard cyanoacrylate will not cure on. At 30 to 70 cP it flows into a tight joint, and the Range Extended chemistry handles plated parts, porous and acidic substrates, and surfaces carrying oil, silicone grease, or release agent. It fills to .004 in and is offered in a 20 gram bottle.

What does non-surface-sensitive cyanoacrylate mean?

It means the adhesive still cures on surfaces that would stop a conventional cyanoacrylate. Standard CA cure is inhibited by acidic surfaces and blocked by oily or greasy films, which is why the same bottle can bond one part in seconds and sit wet on another. Non-surface-sensitive grades, which Pacer calls Range Extended, are formulated to bond anyway. RX-50 handles silicone greases, oils, release agents, plated parts, porous materials, and acidic substrates.

What is the difference between Pacer RX-50 and E-40?

Surface tolerance versus strength. Both run 30 to 70 cP, both fill .004 in, and both meet MIL-A-46050C Type II, Class 1. E-40 is stronger on clean metal, 2700 psi steel shear against 2300 and 4700 psi tensile against 4000, plus a published 7 to 10 ft-lbs impact figure RX-50 does not have. RX-50 bonds oily, plated, porous, and acidic surfaces that E-40 cannot, and on EPDM it fails the rubber where E-40 reaches only 100 psi. Clean metal, use E-40. Difficult surface or rubber, use RX-50.

Is Pacer RX-50 a replacement for the discontinued RX-5?

It’s the closest grade on chemistry, but it is not a direct replacement. RX-5 was 2 to 10 cP and wicked into a closed joint by capillary action. RX-50 is 30 to 70 cP, so it goes on before you close the joint rather than after, and gap capability drops from .002 in to .004 in. There is currently no non-surface-sensitive wicking grade in the Pacer line. Call us if that combination is what your process needs.

How much gap will Pacer RX-50 fill?

Typical gap capability is .004 in, the tightest of the current RX grades. If your parts sit looser, RX-100 fills .005 in, RX-500 fills .008 in, RX-700 fills .010 in, and the RX Gel allows .020 in. Adding more adhesive does not bridge a wider gap, it just leaves an uncured core.

Does Pacer RX-50 bond EPDM rubber?

Yes, and it’s one of the strongest cases for the grade. In ASTM D-1002 testing RX-50 gives substrate failure on EPDM, meaning the rubber tears before the bond line lets go, and SBR is the same. Pacer’s general purpose E Series grades reach only 100 psi on EPDM. For rubber gaskets, seals, and trim on close-fitting parts, this is the grade.

Does Pacer RX-50 come in a larger size?

Not currently. The 20 gram bottle is the only package Pacer offers in RX-50, and it’s sold in case quantity of 10. RX-100 and RX-500 are the two Range Extended grades available in a 1 lb bottle. If you’re standardizing a production process on RX-50 and need volume, call us first so we can look at options before you build the process around a package that isn’t there.

Will Pacer RX-50 run on a vertical surface?

Yes. At 30 to 70 cP this is a low viscosity liquid and it will run down a vertical or overhead face before it cures. Fixture the part flat where you can. If the part cannot be reoriented, the RX Gel is the only grade Pacer rates as non-sag and non-running, though note it is not certified to MIL-A-46050C.

How should Pacer RX-50 be stored, and what is the shelf life?

Refrigerate unopened bottles for optimal results. Once opened, store in a cool, dry location away from heat sources. Stored that way, expect a one year shelf life.

Questions on Fit

Got a part a standard cyanoacrylate won’t bond? Call (800) 220-1966 or email [email protected] and tell us what the surface has been through.