Where does the Triumph Spitfire rust?
A separate chassis doesn't mean the body is cosmetic. The Spitfire's body tub adds stiffness, so rotten sills let the car flex, and the chassis outriggers rust too.
Rotten sills on a Spitfire can make the body tub flex and door gaps change. Support the tub properly before cutting sills out.
The 3D model could not be loaded. The notes below still apply.
Tap a pin or an area below to see where it rusts. Drag to turn the car.
- Structural: affects strength
- MOT failure risk
- Cosmetic, but it spreads
The model is a 1976 Spitfire 1500; earlier Spitfires rust in the same places. The underside is a photograph of a real car's chassis.
Where it rusts, worst first
Body sills
- What to look for
- Bubbling sills, door gaps that open or close with the hood up or down, doors that drop when opened.
- Why it rusts here
- Water draining from the doors and A-posts into the sill box section.
- Repair
- Sill replacement with the tub braced.
Kit for this job
- Dinitrol ML Penetrating Cavity Wax, 2 x 500 mlBest overall in our cavity wax test; thin enough to creep into folded seams and it stays activeBuy on Amazonour test
- U-POL Weld#2 Zinc Weld-Through Primer, 450 mlOn every joint face before a panel goes in; it conducts, so you weld straight through itBuy on Amazonour test
- VELPAX 140A MIG WelderBest value all-rounder in our welder test, if you are doing the panel yourselfBuy on Amazonour test
- U-POL Tiger Seal, grey, 310 mlOver every new seam before paint; stays flexible and takes paintBuy on Amazonour test
Chassis outriggers and rear rails
- What to look for
- Rot in the outriggers that support the body and corrosion on the rear chassis rails near the differential.
- Why it rusts here
- Mud collects on the flat sections and they're rarely treated.
- Repair
- Outriggers available; chassis repair sections or replacement.
Kit for this job
- Evapo-Rust C700Best overall in our remover test; strips rust to bare metal without harming sound steelBuy on Amazonour test
- Hycote High Zinc Primer, 400 ml (pack of 2)Over 60% zinc in the dry film; on bare, clean metal onlyBuy on Amazonour test
- Dinitrol 4941 Black Underbody Wax, 3 x 500 mlBest overall in our underbody test; a wax film that stays flexible, where bitumen cracks and traps waterBuy on Amazonour test
A-posts
- What to look for
- Rust at the base of the A-post and around the door hinge area.
- Why it rusts here
- Water runs down from the windscreen frame.
- Repair
- Repair panels; affects door alignment.
Kit for this job
- Dinitrol ML Penetrating Cavity Wax, 2 x 500 mlBest overall in our cavity wax test; thin enough to creep into folded seams and it stays activeBuy on Amazonour test
- U-POL Weld#2 Zinc Weld-Through Primer, 450 mlOn every joint face before a panel goes in; it conducts, so you weld straight through itBuy on Amazonour test
- VELPAX 140A MIG WelderBest value all-rounder in our welder test, if you are doing the panel yourselfBuy on Amazonour test
- U-POL Tiger Seal, grey, 310 mlOver every new seam before paint; stays flexible and takes paintBuy on Amazonour test
Floor pans and boot floor
- What to look for
- Holes in the floor, rusty boot floor and spare wheel well.
- Why it rusts here
- Leaking hood and seals.
- Repair
- Panels widely available.
Kit for this job
- Bilt Hamber Hydrate 80Best value in our converter test; for floors you cannot strip bareBuy on Amazonour test
- Dinitrol 4941 Black Underbody Wax, 3 x 500 mlBest overall in our underbody test; a wax film that stays flexible, where bitumen cracks and traps waterBuy on Amazonour test
- U-POL Tiger Seal, grey, 310 mlOver every new seam before paint; stays flexible and takes paintBuy on Amazonour test
Bonnet lower edges and wheel arches
- What to look for
- Rust along the lower edges of the one-piece bonnet and around the front arch lips.
- Why it rusts here
- Mud thrown up inside the bonnet sections.
- Repair
- Bonnet panels and repair sections available.
Kit for this job
- U-POL Weld#2 Zinc Weld-Through Primer, 450 mlOn every joint face before a panel goes in; it conducts, so you weld straight through itBuy on Amazonour test
- VELPAX 140A MIG WelderBest value all-rounder in our welder test, if you are doing the panel yourselfBuy on Amazonour test
- U-POL Tiger Seal, grey, 310 mlOver every new seam before paint; stays flexible and takes paintBuy on Amazonour test
- Dinitrol ML Penetrating Cavity Wax, 2 x 500 mlBest overall in our cavity wax test; thin enough to creep into folded seams and it stays activeBuy on Amazonour test
Inspection tips
- Open and close the doors: sticking or dropping doors point to sill or A-post problems.
- Lift the bonnet fully to inspect chassis, outriggers and bonnet edges in one go.
- Check the chassis around the differential mounts from underneath.
Inspection kit
- OSRAM LEDinspect Pocket 200Slim, bright and rechargeable; it reaches behind trim and up into archesBuy on Amazonour test
- Blue Spot Tools 07327 telescopic magnetWeak enough to drop off over filler, which is the point; the telescopic stem reaches under sillsBuy on Amazonour test
- Rolson telescopic inspection mirror with LEDsFor the back of sills and inside archesBuy on Amazonour test
- Draper soft-grip awl, 75 mmPressed, never stabbed, along sills and floors; a thin screwdriver you already own does the same jobBuy on Amazonour test
Related guides
Frequently asked questions
Where does a Triumph Spitfire rust?
Body sills, chassis outriggers and rear rails, bonnet lower edges, A-posts and floors.
Does the Spitfire's separate chassis make body rust less serious?
No. The body tub adds rigidity, so sill rot is structural even though there's a chassis underneath.
3D model: triumph Spitfire cabriolet convertibe by Configcars / maxipub, CC BY 4.0; simplified for the web, badges and plates removed.