Metal Panel Bond and Weld Bond

When a panel on the rear of the vehicle needs to be repaired, follow these best practices will ensure the job gets done quickly and efficiently.  



Panel Removal

Remove the old panel and straighten the substrate to be bonded. You want to ensure a good fit for structural integrity and appearance.

Metal Panel Bond and Weld Bond Best Practice - Step 1



Surface Cleaning

Clean the bond line on both panels with panel and adhesive cleaner, and dry bond lines with a clean wipe to eliminate any contaminants from the bonding area.

Metal Panel Bond and Weld Bond Best Practice - Step 2




Grind the bond line on the vehicle and new panel with a 36 grit disc to remove any paint and corrosion, and to establish a “tooth” for the adhesive. If welding will not be done with a resistance welder, or if using epoxy, then spray Zinc Rich Weld-Through Primer where the panel will be welded. Do not apply adhesive over the weld-through primer. Make sure to remove any excess primer where a top coat will be applied. The objective is to make sure there is corrosion protection for areas to be welded.

Metal Panel Bond and Weld Bond Best Practice - Step 3



Dry Fit

Dry fit the new skin or panel to ensure proper fit.

Metal Panel Bond and Weld Bond Best Practice - Step 4



Adhesive Application

Apply adhesive along the entire bond line on the vehicle and panel, brushing out the adhesive where necessary to cover all bare metal to ensure 100% coverage for strength and corrosion protection.

Note: Do not apply adhesive where the Zinc Rich Weld-Through has been applied.

App-Best Practices-Metal Panel Bond-Weld Bond-Step 5



Re-apply Adhesive

Re-apply a bead that is one-half the width of the bond line on the panel where material has already been brushed out then fit the panel into place.

Note: Once the panels are glued together, they should not be pulled apart as this will break the bond strength. However, they can be moved in a sliding action as long as they maintain contact with one another.

Metal Panel Bond and Weld Bond Best Practice - Step 6




Clamp or screw panel in place for a traditional bond. Make sure you are using products that have glass beads in them to prevent over clamping. You can use a resistance welder to weld through the acrylic metal bonders while they are in a wet or cured state. You can also use a resistance welder with the epoxy panel bonder, but only while it is in a wet state. If you are using any other type of welder, do NOT weld through or within 2" of the adhesive. After the recommended clamp time has passed, remove the clamps. Any excess that needs to be removed can be done with a Rapid Strip disc.  

Note: The full cure time (which is different than the clamp time) for an acrylic metal bonder is 8 hours. The full cure time for an epoxy panel bonder is 24 hours. You want to allow the adhesive to build appropriate tensile strength for the bond between the vehicle and the panel.

Metal Panel Bond and Weld Bond Best Practice - Step 7


The vehicle is now ready to continue on its journey through the shop of full collision repair if any additional repairs need to be made before getting re-painted.



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