Plasti-Mend is a specially formulated mix of solvents and plastic resins. When applied to an ABS plastic, it begins melting the plastic it is applied to. It starts to dry on the surface or “skims over”, slowing the evaporation of the solvents and allowing the new plastic to continue melting into the plastic it is applied to. Application of additional coats enhances this process as well as building up a thicker supporting layer of new plastic. As it continues to dry the new layer of plastic is effectively bonded to the melted plastic it was applied to. This process melts the plastic it is applied to back together. It also provides a new supporting layer of plastic that is melted together with the plastic it is applied to. This creates a repair that is stronger than the original item.
How is this different from epoxies and other adhesives?
Other adhesives stick to the plastic but do not melt into and bond with the plastic they are applied to. These will sometimes effectively “plug up” the hole but they can lose adhesion and separate, causing failure. The only two sure methods of repair are thermal welding and chemical welding such as provided by Plasti-mend. Both of these methods melt the plastic back together. Other adhesives do not.
Why not use ABS plumbing cement?
Plumbing cement is formulated to melt fittings and pipe together. Plasti-mend is formulated as a brush on topical repair. This requires different solvents and different mixes of plastic resin. Although ABS plumbing cement can be used on smaller repairs with some success, it does not usually provide the bonding which Plasti-Mend is designed for.
Is thermal welding better than Plasti-Mend?
Thermal welding is very effective and is the only other sure method of repair but it requires special equipment and some practice to be proficient. Due to this, there are a limited number of service centers that offer thermal welding. Plasti-Mend is chemical welding and does not require extra equipment or special skills. It can be brushed on and, if applied correctly, can be just as or more effective than thermal welding. Many times cracks are due to stresses from the original thermoforming process when the tank is manufactured and the plastic is stretched too thin. Plasti-Mend can be applied over larger areas to strengthen areas where this is the problem. Due to labor cost and application, larger area repairs are not generally considered practical with thermal welding. Thermal welding basically repairs the item to its original condition—Plasti-Mend makes the item stronger than the original.
How soon can I use the repaired item?
In most cases the item can be used within a few hours of repair. This will depend on many factors such as the size of the repair, temperature and use. If the unit is to be sitting still it could be used sooner than if it was to be subjected to the stresses of movement. Small repairs in 50-80 degree weather can be used in 2-4 hours. Larger repairs such as a 3-4 inch hole would require 12-24 hours to guarantee success. It takes 4-7 days for a repair to reach maximum strength.
Can I speed up the drying process?
Plasti-Mend works by allowing the solvent to melt into the plastic it is applied to. It is best if this is given the full time.
Can I use Plasti-Mend in freezing weather?
Plasti-mend can be used at about any temperature but the drying time will be a little longer and it can be a little more difficult to apply. If the Plasti-Mend is brought to room temperature and the tank warmed with a heat gun, it can make application easier.
What are the main reasons Plasti-Mend would fail?
If used on the correct plastics,there are basically three reasons for failure:
Improper surface preparation. The surface must be clean and dry. It should be cleaned and primed with the Cleaner/Primer. There should be no moisture. If any moisture is on the surface or in the cracks etc., the Plasti-Mend cannot bond to the plastic properly.
Improper application. The Plasti-mend should be brushed on in a thick coat to allow for the bonding process. There should be at least three coats applied, more for larger or difficult areas of repair. The second coat should be applied 1-4 hours after the first, if possible, to provide more bonding action. Timing is not critical on later coats.
Evaporation of solvents. The bonding process relies upon the correct amount of solvents in the product when it is applied. If too much of the solvents evaporate and the product becomes too thick, Plasti-Mend will not bond properly. It should be about the consistency of a heavy syrup or honey when it is applied.
Can Plasti-Mend be applied over other repair materials?
Part of the strength of the Plasti-Mend is the ability to bond into the ABS plastic which it cannot do with anything on the ABS. If the old repair material did not stick to the ABS well enough to repair it the Plasti-Mend cannot stick to it. So, anything down to the ABS plastic should be removed . Sometimes heating the old sealant with a heat gun or even a hair dryer will loosen it so it can be peeled off without too much trouble or you can use a coarse rotary rasp or sanding disc. You don't have to worry too much about damaging the plastic since the Plasti-Mend will repair it with no problem. The main thing is to get a clean ABS surface for the Plasti-Mend to bond into.
I want to carry a Plasti-Mend kit for emergency repairs, is there a shelf life on it?
At this time there has been nolimit established for a shelf life on Plasti-Mend. The only determining factor so far is if the solvents evaporate.
I have some Plasti-Mend left over from my repair, can I save it?
Yes, as long as it is closed tight so the solvents cannot evaporate it should be fine for future use. After sealing the lid, turn the can upside down so the Plasti-Mend can seal the lid to prevent solvent escape.