TECTULby IMR

Fluid conveyance · Anaerobic thread sealants

TECHNICAL DATA SHEET

FT-TC-SEL-ANAER-001

Issue date: August 4, 2026 · Rev. 001

Check the current version

Anaerobic thread sealants — high strength and medium strength

TECTUL · Dispatch across Colombia · Exports to Central & South America

GASTOP is an anaerobic sealant for metal threaded joints: it cures without air, in contact with the metal. High strength (red) fixes semi-permanently — removed with heat and special tooling. Medium strength (blue) is removed with conventional tooling, for frequent maintenance. Both: −54 °C to +150 °C, full cure in 24 hours.

SKU VT-58699 (high strength) and VT-58700 (medium strength) · 2 grades in 10 ml and 36 ml presentations · sold by the jar

1. Technical specifications

Comparison: medium strength versus high strength

General specifications

The values in this table come from the factory data sheet of each reference (Gastop High Strength and Gastop Medium Strength, ITW Colombia/Unifix). The SKU, commercial sizes (10 ml and 36 ml) and sale unit come from the TECTUL catalog — not from the factory data sheet, which also offers a 10 g presentation TECTUL does not publish as its own reference.

2. How an anaerobic sealant cures

No air and metal contact: the dual cure condition

An anaerobic sealant stays liquid inside the bottle because atmospheric oxygen acts as an inhibitor: as long as dissolved oxygen is present, the free-radical chain never starts. Once applied between two metal parts and assembled, the product is confined in an air-free space — the "anaerobic" condition that names the family. That absence of oxygen is necessary but not sufficient: the second trigger is contact with metal ions (typically iron or copper) present on the parts' surface, which break down the inhibitor and set off the acrylic's free-radical polymerization. The two conditions together — zero air, an active metal ion — explain why the product cures inside the assembled thread and not inside the bottle nor on the excess left exposed to air.

Why it does not cure on plastic

A thermoplastic substrate provides no catalyzing metal ions, so the reaction trigger never activates: the product can remain wet or uncured indefinitely. In addition, chemical contact with some anaerobic sealants can soften or stress-crack certain plastics. That is why this product family is specified exclusively for metal-to-metal joints; on a plastic threaded fitting (PVC, PP-R) thread sealing is solved with PTFE tape or paste, not an anaerobic sealant.

The limit that prevents returns: the maximum gap

Each grade has a manufacturer-published maximum application gap — 0.45 mm for high strength, 0.15 mm for medium strength — the maximum radial space between the two threaded surfaces for the product to cure fully. If the thread's actual gap exceeds that value, oxygen keeps diffusing into the product film and the reaction never completes: the result is a tacky joint, a lower breakaway torque than published, or a joint that never fully hardens. This is the most common cause of a "the sealant did not bond" complaint: it is not a lot defect, it is a thread with more gap than the applied grade can cure — in that case a grade with a higher allowable maximum gap should be evaluated, or the thread's mechanical fit reviewed.

Passive metals: why an activator is sometimes needed

Stainless steels, anodized aluminum, passivated titanium and some coatings (zinc, cadmium, black oxide) form a surface oxide layer that isolates the base metal and blocks the metal-ion mechanism described above. On those surfaces cure can remain incomplete or take much longer than normal even with a correct gap. Standard practice in the anaerobic fastener industry is to apply an activator/primer to at least one of the two surfaces before the sealant, which restores the chemical trigger. Gastop's factory data sheet does not declare its own activator for this line; if the project uses stainless fasteners or passive coatings, a compatible activator is confirmed on quotation.

3. Application

Preparation: cleaning beforehand

Both parts to be assembled are cleaned of dust, grease and oil on the thread before applying the product — residual oil is the most common reason a sealant fails to cure, because it separates the product from the metal and blocks the contact that triggers the reaction. Shake the bottle before each application.

Amount of product

The manufacturer recommends covering the first three threads with the bottle's applicator tip, applying to both parts to be assembled — filling the entire thread length is not necessary. Excess product does not improve sealing: the excess left exposed to air outside the joint does not cure, does not contaminate and is easily cleaned, but adds no extra strength.

Assembly and fixture time

The parts are assembled immediately after applying the product and must not be moved during the 15-minute fixture time. Cure keeps progressing after that point until it completes in 24 hours. The joint's service tightening torque (the system's operating torque, distinct from the sealant's breakaway torque reported in section 1) should only be demanded of the joint once the fixture time has elapsed, and to count on the full breakaway torque from the comparison table it is best to wait for the full 24-hour cure before putting the line into service at full load.

Handling and storage

• Metal particles must not be allowed into the bottle during use: they catalyze polymerization inside the container and render it unusable.
• The product must not be repackaged outside its original container.
• Store in a cool, dry place, below 25 °C, protected from direct sunlight, in the closed original container; once opened, storage time should be short.
• Apply in ventilated areas and use polyethylene, neoprene or latex gloves for prolonged skin contact; on eye contact, flush immediately with plenty of water.

4. Frequently asked questions

How do I remove a screw fixed with high-strength sealant?

With localized heat: the general practice in the high-strength anaerobic fastener industry is to heat the screw head or the joint area above 250 °C (with a heat gun or torch, for example) and unscrew it while the part is still hot, because the polymer's strength rises again as it cools. Gastop High Strength's factory data sheet confirms that "special tooling is required to disassemble the parts", but it does not publish its own removal temperature; the 250 °C figure is a general reference from high-strength anaerobic chemistry and should be confirmed before applying it to a specific part, especially one that is heat-sensitive.

Does it work on stainless steel fasteners?

Cure can remain incomplete without help: stainless steel forms a passive chromium oxide layer that blocks the metal-ion trigger the anaerobic sealant needs to cure (see section 2). On stainless, galvanized or passively coated fasteners a compatible activator/primer is recommended before applying the sealant. Gastop does not publish an activator of its own in its factory data sheet; the activator for a given project is confirmed on quotation.

How long does it take to cure?

15 minutes of fixture time —do not move the parts during that time— and 24 hours of full cure to reach the breakaway torque reported by the manufacturer, the same for both grades. Torque development is progressive: at 15 minutes there is already partial strength (2.2–6.8 Nm depending on grade), it rises at one hour (6.8–18 Nm), and reaches the full value from the comparison table at 24 hours.

Does it seal threaded pipe joints under pressure?

Yes, within the use the manufacturer declares: Gastop is designed for assembling threaded joints in gas (natural and LPG) and water installations, and acts as a thread sealant in addition to a locker. The factory data sheet does not publish a maximum service pressure for the sealed joint — actual performance depends on the thread's mechanical fit, on the gap not exceeding the applied grade's maximum (0.45 mm or 0.15 mm), and on the joint's tightening torque. For a specific design pressure, TECTUL confirms the application on quotation.

What is the difference between the high-strength and medium-strength sealant?

Breakaway torque and intended use: high strength develops more than double the 24-hour breakaway torque of medium strength (22.6 Nm versus 9 Nm) and is removed with special tooling — it is the semi-permanent fixture. Medium strength is removed with conventional tooling and is specified on parts that will receive maintenance or short- to medium-term disassembly. Both grades share service temperature, fixture and cure times, and declared chemical resistance.

Is the excess left outside the thread a problem?

No. The product left exposed to air, outside the threaded joint, does not cure —because it lacks the air-free condition— and does not contaminate; it is easily cleaned before or after the joint hardens. This behavior differs from inside the thread, where it is confined without air and does polymerize.

5. Application notes

6. Technical notice and limitation of liability