• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A TR3 undercoating?

Share this page

T

TruCraft

Jedi Hopeful
Offline
I have almost got my TR3 ready for the road.
I was wondering what everyone thinks about undercoating the underside of the fenders.
Stock, I guess they were painted with no sealer.
They did rust because of this!
I have used all SS mounting hardware and want to undercoat and use a tar based panel sealer around all under body gaps to keep out the rain.
I want to protect the car better than the factory did, and make it last another 50 years!
It won't be stock......But
Lyle
 
Not stock but if you are going to use her I'd consider it for sure. Make sure to take picture of her w/out the undercoating first so people don't think you are trying to hide anything.

I'm going to undercoat mine, but I'm sure other will weigh in here with other ideas and suggestions.
 
I restored my 1958 TR3A finishing in 1990. I had all the panels, doors and the fenders painted separately. Then in 2007, I took them all off again to have them re-sprayed because of stone chips on the outside and a few up under the fenders. There was no rust at all - anywhere. I have no seam sealer or dum-dum in the joints but every joint was pre-painted face to face.

I have no undercoating. In those 17 years, I drove 94,000 miles and I'd guess that only about 4,000 miles was driven in the rain. I park the cat inside when I'm at home and I only drive it in the summer. I wash it about 5 to 10 times every summer. It dries in about 10 minutes.

If you plan to drive in the rain a lot during the next 50 years, then, go ahead with the undercoating. If it's raining, are you going to go out in the TR for a quart of milk ? Or would you use the family car ? If you are planning to drive your TR only in the sunshine, then you don't need undercoating.

I bought my TR3A brand new in May 1958 and one of the options was "undercoating". It was the worst decisions I could have made. The tarry substance they sprayed up under there dried out and split with cracks in it. When I drove in the rain, the water would go up the inside of the fender and get trapped in the cracks and it collected in the "envelopes" where the undercoat had separated from the inner surfaces of the fenders. It would be wet there for days. In 1987, during the restoration, I had to MIG weld into place all new captive boxes and seams because of the rust.

If I were you, I wouldn't apply any undercoating.
 

Attachments

  • 16070.jpg
    16070.jpg
    52 KB · Views: 279
Amazing car Don, just fantastic. Keep in mind though that Lyle lives in Florida, and it is humid and frequently wet with rain storms that can blow up out of nowhere.

Maybe just doing a good job applying seam sealer?
 
Thanks for the replies.
Don, your car looks great!
Yep, we could drive our TR's year round in FL, but sudden rain storms are the biggest problem.
Will carry a car cover for sure!
The fender areas have lots of gaps for water to enter and rust!
I will use seam sealer at least.

With no inner fenders the sand and stones will beat the paint!
The new spray undercoatings have a texture and stay "rubbery".
I don't want to spray on a heavy coat of undercoating over everything, just a layer to protect the bare fenders. I want to be able to remove the bolts easily.
I did my Opel GT 10 years ago and it has held up great.
The sand on the road here acts like a sand blaster!
After seeing & fixing all the rusted areas around the fenders I want to do something to keep it from happening again.
Lyle
 
Rubberized undercoating SHOULD protect your wheel arches from stone chips. It won't really help protect the car from rain.
I undercoated my TR3 17 years ago and have since sprayed it a few times with Waxoyl to keep it pliable. However, I noticed last year that there were a few stone chips that had penetrated through the undercoat and paint and the rust had spread to the size of about a quarter (notice how I am picking up the language!!) I have since sanded and brushed the rust, treated it, repainted and then undercoated the areas again.
I use undercoat because I use the car for the occasional historic rally when it is used on rough roads and a lot of stones fly up into the arches. If I only used the car for road use, I would just paint under the wheel arches - even in this rainy Scottish climate. That way any chips would be visible and could be sorted quickly before any serious rust forms.
IMG_1181.jpg
 
Not a TR3 I know, but my TR8 was never rust proofed. I drive it rarely in rain and never in snow. I wash and wax it regularly during the summer months. It is 29 years old now.....

I have zero rust anywhere on the car.

When i get a hold of a TR3 project, I intend to paint everything, but no rust proofing or dum-dum in the joints. The research I have done so far suggests it simply is not necessary based on how the car is used ( sunny day drive about).

My two pence (see I am picking up the language!) :smile:
 
Nick --
Don't all of the other Scots laugh and point at where you sit in your car??? Do they say things like, "You're not from around here, are you???"
 
I have to agree with Don. If the car is painted properly (and todays 2-part acrylic paints are marvelous) there is no need to undercoat. I realize that there are many who do not agree. What I do not like about undercoating is that it can hide rust and corrosion and thus can give you a false sense of secrurity. The only exception I would make is to use something like wax oyl for the inside of boxed-in members. However, even those can be painted. We painted the inside of the rockers by pouring in paint and sloshing it around.

Good luck,

Frank
 
Moseso said:
Nick --
Don't all of the other Scots laugh and point at where you sit in your car??? Do they say things like, "You're not from around here, are you???"
Click to expand...

Yes, it happens all of the time, regardless of whether I am in the car or not!!
 
angelfj said:
Nick, when was that photo taken. I could have sworn that you converted to right-hand steering!
Click to expand...

Frank,
That was 2007. The car is still left hand drive. It doesn't have the holes in the bulkhead for rhd steering and I keep telling myself that I should move to somewhere hotter in Europe where they drive on the right!
Nick
 
On my TR6 I painted the inside of the fenders with a strong rust proofing primer then top coated with spray on truck bed liner. The truck bed liner is a vinyl/plastic compound and has a nice texture to it. I never liked the rubber type undercoatings. just my 2c.
 
I used a bit of undercoating, the paintable type, in the wells. I just used a bit where the rocks get thrown, directly over the tire and the back flat area behind on the fronts and top side only on the rears. I painted over the undercoating. It's hardly noticable and really helps with the chips or dents.
I had one dent (visible from above) from a rock throw that convinced me to do this. None since.
I do drive on other than hardball roads.
 
Back
Top