- What linoleum can be welded
- Differences between types of cold welding glue
- The necessary conditions
- Trimming and trimming linoleum
- Glue application
- Cosmetic seam treatment
The need for seamless installation of linoleum over a large area is due to the requirements for appearance and safety. It is customary to weld linoleum in office, industrial, educational and commercial premises, and today we will describe in detail the cold method of joining linoleum canvases.
What linoleum can be welded
Quite a few varieties of linoleum are suitable for cold welding, with the exception of natural. This happens because of the requirements for high homogeneity of the seam: the chemical reagent dissolves the edges, filling the pores with plastic compound and thus making the seam as homogeneous as possible. The organic components of natural linoleum do not dissolve, and therefore the seam has less wear resistance and can be torn with much less effort, and there is also no reliable sealing.
There are three types of cold welding adhesives. Two – for seamless laying of PVC (type A) and polyester (type T) linoleum, one more – for repair work (type C). Compliance of the glue with the area of application must be strict, because not only the consistency is different, but also the ratio of the main solvents to the filler.
Usually, household linoleum, which is not suitable for thermomechanical welding, is joined by cold welding. At low operating loads (class 2 with any intensity), linoleum does not require such a high strength of the connection, while cold welding proves itself as a much more convenient method. It does not require a special soldering torch, and all work can be carried out without special qualifications.
Differences between types of cold welding glue
The types of glue discussed above have a number of additional differences that limit their scope. Type A glue is intended for filling thin joints with precise trimming, that is, it is used exclusively for laying linoleum. The main difference is a more fluid consistency, which promotes quick and deep penetration into the pores..
The type C repair compound retains its shape better due to its thicker consistency. It can be used to fill joints 2-3 mm wide, resulting from cracking of already laid linoleum. A feature of this composition can be called a rather pronounced shrinkage (about 20-30% of the initial volume), which is why the joints are filled in several applications with a frequency of 2-3 hours..
The third type of welding is intended for joining linoleum exclusively on a polyester-felt base, where type A glue is not used. In terms of the method of application and consistency, these compositions are identical, but type T is also used for repair work. All three types of adhesives are transparent and therefore the seams can pass through light and dark contrasting areas of the design without creating visual disturbances.
The necessary conditions
For welding, both edges of the linoleum must be tightly glued to the base and fit together with the formation of a gap of as little thickness as possible. Before cold welding, linoleum must be glued without fail, the only exceptions are applications. In the latter case, due to the small size of the parts, linear shrinkage after gluing is not very pronounced and can be compensated by a plastic joint filler.
The surface of the subfloor in the joint zone should not have protrusions and significant curvatures of the plane. Cold welding can withstand the load well if the seam is not subject to deformations, while when the seam area peels off from the base, a crack along the joint will reappear quite quickly due to fracture of the edges.
Cleanliness and degreasing of the seam is the third prerequisite. The presence of dust at the facility, saturation of linoleum with moisture, welding without limiting the operation of the coating – all this is categorically unacceptable for the exact observance of the work technology. The edges of the canvases are thoroughly cleaned both along the edges and the adjacent 7-10 cm stripes on the front and back surfaces.
To increase the reliability of fixing and immobilizing the edges for the period of hardening, double-sided tape is glued under the seam. This can be omitted only if both abutting edges are securely glued to the base and rolled. In this case, the seam will be fixed not only to the edges, but also to the surface of the subfloor. When cracking, such a joint can be easily repaired by reintroducing a type A compound. An adhesive lining is also needed if the linoleum joins as the rolls are laid and one of the sides is not yet glued. This order of work should be avoided, the reliability of welding in this case is much lower.
Trimming and trimming linoleum
Ensuring a minimum thickness of the joint is necessary not only to ensure high strength and invisibility of the joint, it also helps to reduce the consumption of expensive glue. With a joint thickness of 0.5 to 1 mm, the consumption is 2 grams per meter. The consumption of type C glue increases in proportion to the increase in the gap, taking into account the increased shrinkage values.
When laying new linoleum without a pronounced pattern, it is joined by overlapping trimming. The edges overlap each other about 35–40 mm, then press down a metal strip in the center of the fold and make one precise and even cut along it along the joint. When moving the bar, it is recommended not to remove the blade from the cut. Should the edge be at an angle of 20–25? to the horizontal to maintain a straight cutting direction. In fact, it is important to cut only the surface protective layers along a common line, ensuring the invisibility of the seam, and all hidden irregularities will be reliably filled with glue..
If there is a pronounced pattern on the linoleum, such as a parquet pattern or floral ornament, the pattern has to be adjusted along the trim line. The edges of both edges are trimmed separately, setting the plank at the selected key points of the pattern. After adjustment, the protruding places of the edges can be processed with coarse sandpaper or carefully cut off the excess with a sharp blade.
When repairing linoleum, trimming is needed to ensure high adhesion. The torn edges are carefully trimmed by 0.5 mm on each side, exposing the fresh, uncontaminated end. If in this place the linoleum has lagged behind the floor, it is glued back and rolled tightly, waiting for the glue to completely dry before welding the seam.
To prevent cold welding from dissolving the front surface of the linoleum, it is protected with a strip of masking tape about 40-50 mm wide. The tape is glued exactly in the center of the seam and pressed tightly with a roller, excluding the liquid glue getting under the tape. It is imperative to check whether the material of the masking tape reacts with the adhesive.
After rolling, a cut is made on the masking tape exactly along the seam line. The blade must make one pass, being fully immersed end-to-end, so as not to go astray and cut one of the edges. After cutting, the joint is thoroughly cleaned with a vacuum cleaner, while the edges of the adhesive tape are bent upward with an air flow and do not interfere with the contact of the glue with the edge, and the slightest residues of dust are removed from the gap.
All three types of glue are supplied in special syringe tubes with a tapered spout, type A glue is additionally equipped with a needle attachment for fine seams. Before use, remove the plastic insert from the needle, pierce the nose of the tube and screw on the cap with the tip installed. It is necessary to squeeze the composition out of the tube by twisting the tail, while holding the nose with the other hand. Cold welding of linoleum is allowed only in well-ventilated rooms and always with the protection of hands with gloves, and the eyes with glasses.
The adhesive must be squeezed out after the needle or spout has been inserted to the full depth of the seam and touches the bottom of the seam. The composition must first fall on the surface of the subfloor or adhesive backing, and then squeeze out from the bottom up along the entire section of the seam. In this case, it is clearly visible how the beads of glue are superimposed on the previous seam. The thickness of the protruding edge of the glue must be at least 1/3 of the thickness of the linoleum. If thick and hard linoleum is welded, it is recommended to heat up the joined parts with a hair dryer to 40-50? C immediately before the introduction of the glue into the seam..
Cosmetic seam treatment
Curing of cold welding for linoleum occurs within 2-3 hours, during this time the coating must remain motionless, walking on the fabrics being welded is excluded by all means. After the period of hardening, linoleum can be subjected to limited use, after a day the coating is ready to take the full load.
After a day has passed since the completion of welding, the excess glue is cut off with a special scraper. Its blade moves almost flush with the linoleum surface, but a small protrusion of a couple of tenths of a millimeter still remains. If desired, it can be made even less noticeable by polishing with a felt circle with the participation of an ugly paste..