Sandblasting Wheel Rims

[Kameron M]

Stephen, should I have that inner fender blasted and primed or leave it as is for now and take care of the hole first, then blast it and prime it afterwards? Does it make a large difference? Is it a waste to have it prepped and primed and then weld onto it?

[frenchblatter]

Kameron, it's generally accepted it's not good to sand blast body panels. I wonder why you ask the groups opinion and then defend your decision based on the suppliers word. Their hardly going to say say you shouldn't sandblast panels, are they.

For what it's worth I chemically stripped the old paint from all my panels and then rubbed them down to bare metal with sanding discs. Took 7 weeks. The chap at the bodyshop has filled in the small holes with solder (can't use lead anymore) and welded in sections where the rot was extensive.

May I respectfully ask that if you seek advice from those that have spent years renovating old cars, you take heed.

[stephen stierman]

Firstly I don't pay anybody to sand blast thin sheet metal, I use a course wire wheel on a grinder and paint stripper myself as needed. I repair rust by welding than do body work and primer. My offer stands............

[Kameron M]

I haven't had anybody yet question the concept of sandblasting (or blasting in general) to clean up my panels yet. I am going to be speaking to newbury sandblasting this afternoon about their selection of aluminum blast material and the concerns mentioned about panel warpage, because for sure that would be ver' bad.

By the way, good eye steven. Turns out there is an old bondo repair in that door. How you saw that and I didn't... I have no idea.

[Steve Simmons]

Sheet metal can be successfully sand blasted, but the person doing it better know exactly how to do it safely. It's practically an art form.

[Kameron M]

At this point, I'm fairly overwhelmed with the variety of information I have at my disposal.

From what I have seen here, and on other forums: blasting car sheet metal seems like a hotly debated subject that brings out a lot of anecdotes and stories, ranging from successful to less-so. This makes my grey matter itch...

Maybe I jumped the gun on this one a bit. I'm not sure.

Now, my Initial plan going into this process was as follows-
Have the panels blasted, which would remove rust, old flaking paint, and a majority of the old repairs
They would come out of this process in an epoxy primer that bondo and fiberglass would stick to acceptably.
Build the body tub up with the wooden framework that I have, sand areas in need of repair at that point, repair, and re-prime. With the body tub completely assembled, have it shot with paint.

I selected this process on the basis of getting a good layer of sturdy primer atop the metal reliably and afford-ably, considering the condition of my panels as they are.

But now i'm not so sure. Which is a bit inconvenient timing wise, as the sandblasting shop really worked with me to get a quote, and they were going to take my panels in saturday morning this week.

[stephen stierman]

Not to be a smart a$$, but you mentioned you didn't have money to fix a pull starter, but I presume you are paying someone to sand blast your metal? I prefer to buy needed parts and fix stuff as it was and do grunt work myself acceptably with a course wire wheel, grinder, and aircraft stripper because I work cheaply. It is fine on wire wheels, chassis rails, etc. also, but you do get your hands dirty. I don't use fiberglass other than on Corvettes, Loti, and TVR's etc. A thin skim of filler over everything is reasonably acceptable and needed to iron out the slings and arrows of almost 70 years of flying debris and hand formed panels. You can primer over or under filler and you will build up primer surface and block it down to get a nice smooth surface before finish painting. I spotted that rusty door because I have done plenty of this sort of work. This is something you learn by doing and making mistakes, I still make plenty, but I think I am headed in the right direction although running out of time.

[Kameron M]

Saving what i can when I can money wise is important, wether it is a large or small operation, to my understanding: the sandblast and prime route was the least expensive- $850 for the whole operation from the panels as they are to an almost usable state in primer, needing a few spot repairs here and there.

I've never been the greatest at bodywork, however.

I have a reasonable skill level in many operations, though I've not been the most sucessful at bodywork before- though I never put a terrible amount of time into doing so. You are local, and your offer is making my brain itchy.

So I guess I wanted to ask, you've seen the body pictures. How much do you think it would run me to do things your way? Would the result be better?

I think at this stage, I have a number of choices.
1- I can go forward with it, but it sounds from a lot of people this is a bad idea
2- I can pull the panels that are in need of serious repair and deal with them the Stephen way and have the others done at newbury at what I can only assume to be a reduced price I would work out with them.
3- I can cold feet the whole blasting operation and sign myself up fro doing the whole car manually.

[stephen stierman]

Most people will tackle mechanical work themselves, it is just twisting wrenches and following directions, almost anyone with some ability can do it. (oversimplification, I know ) Body repair is something else again; requires some experience and time and some learned skills and can be quite unpleasant and hard work. Looking at your photos, I only see a hole in a wheel arch and some rust in a lower door, both are not difficult to fix. I cannot see the cowling but on the sides under the windshield plinths there is often rust through, you may not have this. In any case welding up these small areas is not difficult. The surface rust can be cleaned off with a sanding disc, a wire wheel, or fine media blasting, the first two you could do if you have time and a place to work. Likely some hammer and dolly work will be needed here and there and you will end up with a skim of filler over some parts of the panels. This is the hard work that does require time and skill and you would have to decide if this is something you wish to try on your own and it is really the part that you see in the finished product. It comes down to how comfortable you are taking on some aspects or all aspects or maybe none at all based upon you skills.

[Kameron M]

Stephen - On the right side of the cowl, indeed one of the holes has rusted away and gotten wider around the window plinth.

I'm fairly not great at bodywork, like I said: at least not panel beating. Filler I could probably get into the groove of using with a few practice tries on something else. Gads.

Correct me if I'm wrong here, but it sounds to me like some of my panels don't need this careful treatment and other's do. As in: the panels with rust damage and more severe pitting are better off done by hand, while the gas tank, wings, hood, running boards, door without the hole, etc could be passed off to Newbury (provided that they are careful about it all) and given a light media blasting followed by a primer coat, then mounted up to the car. It also sounds like from what I am hearing that the panels with the worse rust damage (the door with the hole in it, the cowl, the inner fenders) are more likely to get damaged during the blasting process worse than they are- and the coat of primer will impede resto work and welding.

Correct me if I'm wrong here, please.

[stephen stierman]

Kameron, I could not say that some panels will not need a bit of fill and blocking down, my thought would be that this is highly unlikely, but I could be wrong. I can tell you that virtually every panel on my car needed a bit of work as they all collect a ding or imperfection here or there after being shuffled around for so many years. Everyone that does this sort of thing has a different way of doing it, there is probably no entirely right or wrong way.

[Kameron M]

I feel at this point that I owe newbury sandblasting at least the time of day to talk about the panels without major obvious imperctions. They have told me they undertake car projects regularly and haven't had any serious problems, but it does seem that sandblasting is aggressive for a lightweight car such as a TC.

From the collective whole, it seems clear that fiberglass simply isn't a good idea to fix a rust hole. Pardon my naivite' on that.

Stephen, I can't say no to your offer to help me with the rust holes that I do have. I will set those body panels aside and I really do look forward to learning some from you. I have sandpaper of various grits and half of a brain (at least) and if you are game to do some cosmetic-grade welds on my body for me, that would be fantastic.

I started this process rather assuming such work was a wee bit out of budget and out of the skill set of the friends I have around these parts.

[stephen stierman]

I believe you can email me directly from this site as needed.

[Kameron M]

Well: Don't hang me here folks, but after a lot of deliberation, a meeting with the sandblaster who is going to take care of my car, and seeing a few examples of their work, including in person...
and considering some information I found out about my panels today, I have decided to go through with it.

Here is why, in my case:
To start off with, it turns out that some many years ago, greater than ten most likely, the previous previous owner of the car did a sandblasting of some kind, and then failed to paint the metal in that time... ouch.
What this has left, on my panels, is quite a lot of pitted-in rust, along with a few sections that are now porous (but mostly on the inner fenders)

A few people have confirmed this, the sandblaster, an experienced friend of mine, and some internet searching: that there is only one effective treatment when rust goes this way, and it is sandblasting. An attempt to remove the rust manually will either A- Not be effective or B- thin the panels more than they already are. A media blasting treatment, on the other hand, will clean the rust out of the pits directly, without taking as much off the top, and then the layer of primer over the top will fill in the holes.

The folks at Newbury sandblasting and I spent an hour today going over each and every panel I brought them, and we went over our expectations and what results I should get from each.

Notable results are:

The cowl: this one is severely pitted, and there is rust damage around one window holder. The best solution that could be worked out for it, due to the thinness of the metal, for structural integrity's sake and appearance, is not to weld it, but to build a support under the windshield that will spread out the load exerted through the bolt holes.

The Inner fenders- Review of these has revealed that they are effectively toast. At the point of welding them, it would probably be less effort (and less metal) to make new ones. Given that these are inner fenders- not outer ones- a fiberglass treatment is hardly noticeable... well unless someone is an inner-fender sniffer, at which point we will need to have words. I'm going to patch them, undercoat them, and use them. As an original panel, they are fairly hopeless.

The door- This one I was a bit on the fence about, and these are really an either-or. The hole Stephen found, is presently patched with bondo. It is 3/4 inches wide, by 2 inches long. For this one, especially given its small size, and proximity to structural support behind the repair, seems to be a good candidate for a body filler and a block sanding, after the primer is applied. Evidently, this will stick well without issue over the primer if lightly sanded.

I have heard a number of people raise concerns about the sandblasting process. Just because I am doing it this way, does not mean I didn't put some thought into this, and speak to the people involved, and a few other classic car people that had experience with the Newbury Sandblasting company. They have an employee there who has been sandblasting sheet metal and cars for many years, and he is the one, and only person who will be undertaking this job. I was able to see his work both in pictures, and in person, on cases as bad (if not worse) than mine- and his results. There is absolutely no chance that he will turn my fenders into doritos. They are going to use the finest grit of alum. oxide media possible to cut through the rust, at a low pressure as to not ruin the good metal, and then administer a good layer of durable epoxy primer that will last for many many years.

Stephen, I really do appreciate the offer you made to me. I think if the end circumstances were different, I would have jumped on it, but at this point I have been entirely convinced that the best result that I can get out of what I have is via having the whole of the car media blasted at this point. I will get to see results in three weeks, and I suppose conclusions will have to be drawn then.

By the way, on the original topic at hand: the sandblaster has also had much experience with the kind of wire wheels I brought them. They already had the solution: a rubber plug of the appropriate size is to be inserted at both ends of the hub reciever to protect the splines during blasting and painting. Simple.

[stephen stierman]

Kam, just want to advise two things I take away from your post. The windshield plinths bolt through the cowl and through the timbers behind. The timbers provide the strength to hold the windshield not the cowl. Virtually all of them have rust damage because of the horse hair packing or whatever it was between the timbers and the cowl staying damp behind the metal. All you need is to patch the hole, the timbers take the load. Mine required fairly large sections butt welded in behind the plinths on both sides.

That hole in your door, what you see is the tip of the iceberg. The lower section of TC doors typically rust all along the bottom. I replaced the lower couple inches of both my doors. Throwing bondo into that hole is a temporary fix at best. That area needs to be cut back to clean metal and new metal welded in to affect a permanent repair. I am getting the impression that you friend is more of a sandblaster than a body man!

[Kameron M]

My Friend has no affiliation with newbury, but I understand that. The door with the problem won't cost me any extra to sandblast and prime, even if it is sanded off and welded.

If the load from the windshield is entirely born by the timbers, I think that the rust hole that we see in the cowl won't even be visible with the windscreen plinths installed.

[frenchblatter]

Kameron, you need to repair the cowl. If you don't it will rust again and spread outside the area covered.

Of course if you want to do a renovation again in a few years carry on the way you're going. However, there is only one way to it properly and that's not by "bodging" it.

[frenchblatter]

I've just read your long post and you are wrong!

I have renovated all my panels using a phosphate mix to kill the rust. Sand blasting panels is too harsh and will weaken the metal. A good primer will "fill-in" the pock marks. Primer is very thiinned out filler and is applied to obtain a smooth finish on which to paint.

Your sandblast man will not tell you it's not good practice will he. We have but you're not listening.

This is your decision but if you ask a question then ignore the answers why bother asking the question.

[Steve Simmons]

If it were me, I would repair the metal so that water won't work its way between the metal and wood. Even if it's covered by the windscreen pillars, water may possibly still get in. An ounce of prevention could go a long way in this area.

[Richard Michell]

I am very much with the non-blasters here. I built my TC up a couple of years ago from a pile of parts and panels that had been sitting around in someone's garage for at least 45 years. On some panels there were eight distinct paint layers. The car was originally black, had been primered and repainted to green at some time and then painted once more in red.

I stripped every panel by hand using chemical stripper then a combination of wire wheel and coarse sanding disk.

The good news is that stripper works very well on the older style of paints. If your car has modern epoxy-style paint then that is a different matter. Doing it myself saved several thousand (Australian) dollars. It did not take a great amount of time and was a cathartic experience.

If you have panels as you describe, with rust-filled pock marks from previous blasting, I would be very wary of blasting again. Once you remove the rust, you may have almost nothing left in these pocks. Much better IMHO to wire brush off any loose rust and then use a rust converter (preferably phosphate-based as Norman suggests, not tannin based. The latter is very effective but may give complications re painting).

The converter will change the rust from porous and friable iron oxide to impervious and adhesive iron phosphate. It will thus repair the pocks to an extent, not hollow them out. If you go this route be careful to follow the use instructions carefully. Using an excess and/or not rinsing as instructed will leave acid conditions and make any bare metal more likely to rust.

However, it appears that you are committed to blasting and my comments may not be relevant.