Abrade-Prime

Prime coat with an adhesive such as Lord Corp s Chemlok (silicone-type polymer) diluted with 5—10 volumes of methanol or 

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For previously painted and fireproofed surfaces, the mastic manufacturer should be consulted to assure compatibility with the existing surface, proposed paint primer, and mastic. New galvanized surfaces should be mechanically abraded to ensure adherence of the prime coating. 

Various adhesives can be used to bond polyphenylene oxide to itself or to other substrates. Parts must be prepared by sanding or by chromic acid etching at elevated temperature. Methyl alcohol is a suitable solvent for surface cleaning. The prime adhesive candidates are epoxies, modified epoxies, nitrile phenolics, and polyurethanes. Epoxy adhesive will provide tensile shear strength on abraded polyphenylene oxide substrates of 600 to 1300 psi and 1300 to 2200 psi on etched (chromic acid) substrates.71... 

Polyamide (nylon) Acetone, methyl ethyl ketone 1. Abrasion. Grit or vapor blast or abrade with 100-grit emery cloth followed by solvent degreasing. 2. Prime with a spreading dough based on the type of rubber to be bonded in an admixture with isocyanate. 3. Prime with resorcinol formaldehyde adhesives. Sand or steel shot is suitable abrasive Suitable for bonding polyamide textiles to natural and synthetic rubbers Good adhesion to primer coat with epoxy adhesives in metal-to-plastic joints... 

The prime factor in choosing an abradant is its relevance to service, but it also has to be available in a convenient form and, for anything but ad hoc tests, it is essential that it be reproducible. In consequence of these considerations, abrasive wheels and papers or cloths predominate where cutting by sharp asperities is to be simulated. The abrasive wheel is probably the most convenient, because of its low cost, its mechanical stability, and the ease with which it can be refaced to maintain a consistent surface. Abrasive papers and cloths are cheap and easy to use but are not so readily refaced and will deteriorate in cutting power more quickly. Although basically low in cost, both wheels and papers are a considerable c.xpense when bought as standard reference materials. Materials such as textiles or smooth metal plates are more relevant for some applications, but they abrade relatively slowly, and if conditions are accelerated they give rise to excessive heat buildup. 

Surfaces should be abraded and primed as required and as specified. 

P(4) Joint surfaces must be thoroughly clean, dry and free from frost, oil and release agent. Surfaces shall be finely abraded and primed as appropriate. Where exposed to view, edges of joints shall be masked with tape before priming, which shall be removed immediately after sealing. 

Such mechanical anchoring appears to be a prime factor in bonding many porous substrates. Adhesives also frequently, bnt not always, bond better to abraded surfaces than to natural surfaces. This beneficial effect of snrface abrasion may be due to... 

Material Abrading Cleaning Degreasing Activating Priming Remarks... 

The first step is to prepare the inside of the GRP roof assembly to achieve optimum adhesion to e GRP. Abrading the surface of the fibreglass molding creates a good mechanical interlock for the adhesive. The substrate is then cleaned off with a suitable cleaning agent and primed. Meanwhile, the steel substrate is also treated with a suitable metal primer. Then the adhesive is applied to the steel framework in the form of a triangular bead. To meet the demands of series production, a pump-operated applicator system is used (Fig. 78). 

Prime abraded surfaces with General Electric silicone primer SS-4004 and allow a minimum of 1-h dry time (unprimed surfaces reduce bond strength significantly). 

Performance properties of PL 663 on aluminum grade 2024-T3 (anodized with chromic acid) and primed with PL 691 are listed in Table 5.2. Primer was air-dried for 30 min and baked for 80 min at 138°C. Primer was abraded lightly with Scotchbrite, re-primed and air-dried 90 min prior to bonding. Adhesive was 0.05 cm thick, and cured for 135 min at 152°C and 0.69 MPa. Performance test results for Scotch-Weld nitrile-phenolic film adhesives... 

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