Many front-end collisions result in broken headlight tabs like this.
Today's headlights often feature LED bulbs, moveable elements,
and sensors which greatly increase the complexity and cost of the headlight.
This instructional video shows how to repair this complex headlight tab
using Polyvance s 6225 Tab Magic Molding Putty.
Headlights with broken tabs on top which would be visible to the vehicle owner
must be repaired and refinished to restore the original OEM appearance.
Some headlight tabs are smooth, like this one, which is relatively easy to refinish.
Refinishing is difficult when the tab includes ridges, gussets, and waffles like these tabs.
To ease the repair and refinish of these complex tabs, we will use Polyvance's 6225 Tab Magic Molding Putty.
The Tab Magic putty is pressed into the details on the cosmetic side of the tab to keep the weld on the backside from blowing
through and creating imperfections which would make it difficult to refinish.
We'll go through each step of the repair process on this Toyota Tacoma headlight.
This tab has deep gussets that would be difficult to refinish if we welded both sides,
so we will only weld it on the backside.
Most headlight housings are made of polypropylene with a talc filler.
As you can see on the ID symbol, this housing says PP-TD30, which means that the polypropylene has 30 percent talc filler.
The talc filler makes the plastic brittle and causes it to break off cleanly.
This means that broken tabs normally fit together very tightly as you see here.
To tack the tab firmly in position, melt a staple into each side of the tab.
The sides of this tab are fairly thick, so we'll leave the staple in the tab to give it extra strength.
We are using the thick 6214 straight staple on both sides.
No two headlight tabs are the same, so use whichever staple fits the shape of the tab best.
On one side, due to interference with the headlight itself, we bent the staple to allow access.
The staples don't hold the tab very securely, so don't cut the ends of the staples off until you've welded the tab on.
The next step is to mix and apply the 6225 Tab Magic molding putty.
The putty is pressed firmly against the surface on the frontside to support the tab while welding,
and it also keeps the backside weld from blowing through.
Scoop out equal portions of both the white and green sides of the Tab Magic and flatten them out on a clean surface.
Make two pancakes about the same size and thickness.
Put these pancakes together and start kneading them until a uniform green color
is achieved with no white streaks.
You have to work fairly fast because the silicone putty will start to get hard in about two minutes.
Press the putty firmly into the contours of the tab.
Pile it on high enough to give it some structure when you peel it back off.
Let the putty set up for about twenty minutes before you continue.
When the putty is set up, flip the light over and fixture it to the table.
Using a 6125 carbide cutting burr,
grind a v-groove about seventy-five percent of the way through the plastic along the crack.
This will allow you to do a single-sided weld that will weld all the way through,
while the Tab Magic putty prevents the weld from blowing out too far on the other side.
To further strengthen the repair, it is very important to weld across the crack.
Here, the distance between the gussets is wide enough for some ribbon rod,
so we'll also grind these areas to prepare for welding across the crack.
Now that the surfaces and the welding rods are prepared,
first weld along the crack with the round polypropylene welding rod.
As always, when doing a nitrogen plastic weld, make sure to melt both plastics at the same time
by focusing the hot nitrogen gas at the point where the rod meets the base material.
Melt the base material just in front of the rod and melt the rod just before it comes down onto the plastic.
Apply a light downward pressure onto the rod to fuse the two melted plastics together as you make your pass.
Because the v-groove was fairly deep, we will make two passes with the round rod first.
Allow the weld to cool a bit then reinforce the first weld by welding across the crack.
Here we are using the three-eighths wide ribbon rod between the gussets using the same method:
melting the bottom surface of the rod and the top surface of the headlight tab
and applying a little downward pressure to fuse the plastic together as you make your pass.
Since we are only doing a one-sided weld on this tab,
it's very important to build up as much reinforcing material on the backside as possible.
As long as the buildup on the backside does not interfere with any adjoining parts,
you can apply more welding rod to strengthen the repair.
On this tab, there is an area between the gussets and edge that is big enough for us
to weld some narrow ribbon across the crack to provide further reinforcement of the tab.
Smooth the weld with the airless welder, then let the tab cool completely before continuing.
Since there are no adjoining parts on the back in the corner to interfere with,
we'll weld along the crack one more time with the three-eighths wide ribbon to give it some more strength.
Smooth it with the airless welder again.
Then we'll make one final pass down the middle of the gusset.
You can smooth the hot plastic with the airless welder or with the tip of the nitrogen welder itself.
Force-cool the hot plastic with compressed air.
Never apply stress to any hot plastic part.
Allow it to cool completely before continuing.
Flip the light over and fixture it to the table.
Peel the putty back to see what it looks like from the top side.
As you can see, the putty kept most of the welding rod from pushing through,
but there are some minor imperfections that need to be refinished.
Before we continue, we will cut off and grind the ends of the staples.
A Dremel tool with a coarse sanding drum works best for this.
Grind the ends of the staple slightly flush,
then straighten up the sides of the tab with an angle grinder.
Do some fine detail sanding between the gussets with small sandpaper sticks.
Finishing a headlight tab is just like doing regular bodywork, except at a smaller scale.
Use whatever tools you need to prep the tab for primer.
Apply 1060 Filler Prep adhesion promoter to the raw plastic to help the primer stick.
Let it flash or accelerate the process with a heat gun.
Apply 3043 Black Jack waterborne primer surfacer.
Here we are brushing it on, but it can be sprayed on as well.
After the primer dries, sand it with 320 grit sandpaper.
Use spot putty over any remaining imperfections.
Sand the spot putty after it dries.
We'll spray the next coat of primer, so mask off the areas of the light you do not want to paint.
Spray on more primer as necessary to restore the surface, sanding in between coats.
When the surface has been restored to your satisfaction,
apply a black paint to match the housing.
Here we are using Polyvance's 3701 Bumper and Cladding Coat aerosol paint, which sticks well to polypropylene without adhesion promoter.
As you can see, the finished appearance is very close to the original.
And even though we only did a one-sided weld, the strength of this repair is more than sufficient
to take this headlight to the next collision.
Check out Polyvance's PR-03 Headlight Tab Repair Course for even more strategies on how to repair different types of headlight tabs.
Many damaged headlights, bumpers, and other automotive plastics can be repaired using
supplies, equipment, and training from Polyvance, the experts in plastic repair since 1981.
For more information, go to www.polyvance.com, or call 800-633-3047.