Removing Seam Sealer & Undercoat From Cars

Old seam sealer and underseal are among the most stubborn coatings on a vehicle, and the usual removal methods are slow, smelly and messy. This guide explains how laser cleaning strips them cleanly.

Key takeaways

Seam sealer and underseal are thick, sticky and bonded, making them hard to remove.
Heat softens them but smokes and risks scorching the panel; solvents are messy.
Laser cleaning vaporises these coatings cleanly without solvents.
Clean seams reveal hidden rust and allow proper inspection and resealing.

Why these coatings are so stubborn

Seam sealer and underseal are stubborn because they are thick, sticky, rubbery coatings designed to bond hard and resist removal, often layered up over decades. They do their job too well when you want them off.

They also hide the very areas, seams and the underside, where rust likes to start, so removing them is essential for a proper inspection and repair.

The problem with heat and solvents

Heat softens these coatings but produces smoke and fumes and can scorch the panel, while solvents are slow, messy and leave a sticky residue to scrape and clean. Neither is pleasant or precise.

Working overhead on the underside of a vehicle makes both methods harder and dirtier still. It is some of the worst work in a restoration.

How laser cleaning strips them

Laser cleaning strips seam sealer and underseal by vaporising the coating with controlled pulses of light, without solvents or prolonged heat, leaving the metal clean and ready to inspect. It is far cleaner than the alternatives.

Because it is controllable, it removes the coating without scorching the panel, and it reaches into seams. This is the same precision used across our rust and paint removal work.

Want to run these jobs yourself?

LaserStrip sells and hires FLT-P pulsed fibre laser machines (200W, 300W and 500W) with training and UK support. From £10,500 plus VAT.

Buy a Machine Hire First

Revealing what is underneath

Removing these coatings cleanly reveals any hidden rust in the seams and underside, allowing proper inspection, repair and resealing. You find the problems before they find you.

To strip underseal and seam sealer without the mess, see the FLT-P machines, or hire one to try it on a project.

Frequently asked questions

Laser cleaning is the cleanest method. It vaporises the seam sealer with controlled pulses of light, without solvents or prolonged heat, leaving the metal clean and ready to inspect and reseal, and it reaches into the seams.

Yes. Laser cleaning strips thick, rubbery underseal by vaporising it with light, without the smoke of heat methods or the mess of solvents. It removes the coating without scorching the panel.

They hide the seams and underside where rust starts, so removing them is essential for proper inspection and repair. Clean metal also lets you reseal correctly for lasting protection.

Yes, with the correct controls. It is controllable and non-contact, so it removes the coating without scorching the panel. As with all laser work, proper eyewear, extraction and a controlled area are used.