REMA TIP TOP SC4000 Cement | Bonding Procedures

REMA TIP TOP SC4000 Cement is the CFC free alternative to our well known and proven SC2000 Cement with no compromise to bonding strength or performance. By using SC4000 Cement with the E40 Hardener, natural rubber, neoprene rubber, SBR rubber and others can be bonded to each other, to fabric and to steel without the aid of heat or special equipment.

Description
REMA TIP TOP SC4000 is a two component, room temperature curing chloroprene based liquid rubber adhesive that, when catalyzed with the appropriate amount of E40 Hardener, yields high strength adhesions. SC4000 is ideal for use in lining installations, when bonding rubber to rubber, rubber to fabric, rubber to steel, rubber to concrete, fiberglass, and urethane, as well as the splicing and repair of fabric conveyor belting. Repair to existing rubber lined vessels and rubber components are also recommended using this system.

Mixing instructions
The SC4000 Cement system is comprised of cement and hardener in the ratio of 660 grams of SC4000 Cement to 30 grams of E40 Hardener. The non-catalyzed SC 4000 Cement should be stirred/ mixed thoroughly prior to the addition of any Hardener after which the two components must be thoroughly mixed (stirred) for at least 2 minutes. The mixed portion should be used within 2 hours.
Dispensing from bulk units or drum packaging should be measured/mixed by weight using a suitable weight scale in the above stated grams/kilograms ratio only after proper homogenization or mixing/rolling of the adhesive drum. See details under Storage.

General Rubber Lining Environmental Conditions
Before any surface preparation, or application of the metal primer adhesives or application of any lining material – the ambient temperature and that of the substrate must be at least + 50° Fahrenheit with a maximum temperature of
+ 104° Fahrenheit.
The Relative Humidity should not exceed 85% during the entire lining procedure OR the measured substrate temperature must be a minimum of +5 degrees higher than that of the dew point. Relative humidity, ambient temperature, substrate temperature and dew point must be recorded prior to start of project and at three hour intervals thereafter.

Surface Preparation & Application Methods
Rubber to Steel
All surfaces must be clean, dry and free of oil, paint and other contamination. Steel and other metallic surfaces should be abrasive blasted to a minimum 2-mil blast profile (SSPC –SP10 “Near White Metal Blast Cleaning”) to obtain maximum adhesion. Metal surfaces should first be cleaned with REMA TIP TOP R-50 Cleaning Solvent and then abrasive blasted and cleaned again with REMA TIP TOP R-50 Cleaning Solvent. All abrasive blasting residue and/or dust shall be completely removed by brushing and/or vacuuming. After the surface has been prepared it should be primed with REMA TIP TOP PR 200 Metal Primer. The primer should be allowed to dry completely, approximately 1 hour depending upon atmospheric conditions. After allowing the prime coat to cure or dry for at least 1 hour, proceed with bonding procedures.

Fiberglass
The surface should be prepared by first cleaning with REMA TIP TOP R-50 Cleaning Solvent, then sanded, and re-cleaned with REMA TIP TOP R-50 Cleaning Solvent to help remove all abraded particles. Allow the solvent to evaporate. Then the prepared surface must then be primed with SC4000 Cement. The prime coat of cement should be allowed to completely cure for at least 1 hour (overnight is ideal). After allowing the prime coat to cure, proceed with bonding procedures.

Rubber to Rubber
The surface should be prepared by first cleaning with REMA TIP TOP R-50 Cleaning Solvent to remove all mould releases. Rubber that does not have the special REMA TIP TOP CN bonding layer requires cleaning with REMA TIP TOP R-50 Cleaning Solvent and when dry, buffing to a RMA #4 textured finish. The rubber dust should be completely removed with a dry brush and/or vacuumed before the prime OR FIRST DRY coat of SC4000 Cement is applied to the prepared surface.

The applicator should use a scrubbing-like motion when applying the SC4000 Cement. A scrubbing motion is preferred so that all voids on the buffed surface to be bonded are filled in. After allowing the prime coat OR FIRST DRY COAT to cure or dry for at least 1 hour (overnight is ideal) proceed with bonding procedures.

Concrete
The best surface preparation for concrete is abrasive blasting to provide a clean, dry and sound substrate. When abrasive blasting is not practical, the surface may be ground or acid etched following the manufacturer’s recommendations. All abrasive blasting residue and/or dust shall be completely removed by brushing and/or vacuuming. After the surface has been prepared the surface must be primed OR FIRST DRY COAT with SC4000 Cement. SC4000 Cement must not be diluted for optimum adhesion.

Wood
The best surface preparation for wood is abrasive blasting. Wood must be dry. All abrasive blasting residue and/or dust shall be completely removed by brushing and/or vacuuming. After the surface has been prepared the surface must be primed with SC4000 Cement. SC4000 Cement must not be diluted for optimum adhesion.

Fabric to Fabric
Fabric that is R.F.L. treated should be clean and dry and the number of coats of SC4000 Cement will depend on the weight and weave of the fabric. Take special care to insure all indentations are filled (such as heavy conveyor belt fabric).

Bonding
When applying the SC4000 Cement, a scrubbing motion with a suitable cement brush (e.g. RTT. # 8 or RTT #18) is preferred so that all voids on the surface to be bonded are filled. The first prime coat or dry coat of cement on substrate and rubber should be allowed to completely cure for at least 1 hour (overnight is ideal) before the second coat, or “tack or wet coat” is applied.

To the properly prepared surfaces apply a tack coat of SC4000 Cement to each surface at the same time so they dry at the same rate. As rapidly as possible, apply a uniform coat with a brush. Avoid heavy builds, puddles, uneven coating. Surfaces must dry uniformly. Caution must be given as to not allow the coat to dry too much as this will create inadequate adhesion or be “too dry” between coats.

When surfaces are dry to a tack, about 4-8 minutes, they are ready to bond (if the surfaces become too dry, apply another tack coat to each). Timing is dependent on atmospheric conditions (e.g. colder ~ longer; warmer ~ shorter) A quick test is to test the second wet cement coat with the back of a dry finger, it should feel tacky (somewhat dry) and not leave any cement residue on the back of the finger. Join surfaces and roll from the center to the edges with suitable width rubber roller and /or stitcher with an appropriate amount of surface pressure exerted to bond surfaces together and eliminate air entrapment between substrate and rubber. Use 50% overlapping roller strokes making sure both surfaces fully contact each other and all air is expelled.

TECHNICAL DATA
Bond Evaluation
SC4000 is capable of bonding REMA TIP TOP CN/Rubber to steel in the range of 70-80 lbs. peel per inch width. Bond strengths of fabric to fabric, such as fabric conveyor belting develop over to 500 lbs. in shear dependent on the correct mixing, surface preparation, atmospheric conditions and applicator skill level.