How to Repair Your PVC Tarpaulin
PVC tarpaulin is using polyester fabric as a base cloth, coated with polyvinyl chloride (PVC) paste resin with additives, mildew inhibitors, antioxidants, antistatic agents and other chemical additives. It has the properties of waterproof, mold-proof, cold-resistant, aging-resistant, anti-static and so on.
Although PVC coated tarpaulin can serve over 5 year, we will still inevitably encounter situations of damage. In that situation, we choose repair it instead of buying a new one because PVC tarpaulin’s price is relatively high. The PVC knife coated tarpaulin performs good in tear-resistance. However, with time past, the painting layer or junction part is easy to abrasion. Don’t worry. It is also easy to repair it.
The most common method is to use the waterproof glue. There are specialized PVC knife coated tarp repair adhesives on the market. We can choose the kind that is flexible and weather resistant. Following is the detailed steps.
1. First, we need to clean the broken part that need to repair. Wipe the 10cm area around the hole with alcohol to remove oil and dust and ensure that the bonding surface is dry and clean.
2. Then cut the patch cloth according to the shape of the holes, the diameter should be 2-3cm (round/oval shape is best) bigger than diameter of the hole. Lightly abrade the back of the patch cloth with sandpaper to increase the adhesion of the glue.
3. Thirdly, apply patch adhesive evenly to the edge of the hole and the back of the patch fabric, with the thickness of the adhesive layer ≤ 1mm to avoid overflow.
4. Next, center the patch cloth over the hole and remove air bubbles by applying light pressure from the center outward. Apply pressure with a heavy object (5kg or more) for 24 hours to ensure the glue is fully cured.
5. Finally, apply a waterproofing adhesive (e.g. silicone sealant) to the edge of the patch to form a protective layer. Spray water repellent after natural drying to restore localized waterproofing properties.
After repairing, we also need to test whether the tarp is well repaired. 24 hours after repair, pull the edge of the patch fabric lightly by hand without peeling or lifting. A more reliable method would be to conduct a load test. Hang a 2kg weight on the patch area for 30 minutes. If there is no deformation on the PVC knife coated tarpaulin, that will be suitable for continuous using.
Use a spray can to simulate moderate rain (10mm/h) to wash the repair area and observe whether water seepage occurs. And don’t forget to see whether the patch fabric is close in color to the tarp and has no glue spills or wrinkles around the edges. Surface is also important.
If there is no problem after doing all these testing, your tarpaulin is a good tarpaulin now! But if there is something bad occurs in the testing, you need to repaired that again. Don’t worry. You don’t have to do the repairing step again and again. There are some solutions for your reference.
For this situation, we need to find the reason first.
1. Patch off glue not cured or contamination of the bonding surface: re-clean and extend pressurization time to 48 hours.
2. Uneven application of waterproofing adhesive for edge seepage: patching waterproofing adhesive, curing under pressure.
3. Patch hardening cracking, low temperature environment repair or expired glue: indoor repair at room temperature with freshly opened glue.
4. Patch drum wrapped with too thick an adhesive layer or without removing air bubbles: apply glue thinly and remove air bubbles with a roller.
For long-term maintenance, we need do the regularly testing to avoid the accidents. Quarterly inspection of patch areas and light compression testing for bond strength. Prior to the first rain after the repair, focus on spraying water repellents to strength waterproofing. Avoid intense stretching or rubbing of the repaired area for 3 months. This can be helpful in avoiding secondary damage.
Usual maintenance is also very important! Before the tarp is put away, be sure to dry before folding. Damp state storage is particularly easy to breed mold. Sprinkle some baking soda when storing, which can prevent moisture and odor. If you find that the seams have a slight open line, hurry to use the needle and thread reinforcement. Do not wait for the crack getting bigger before processing.