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Thread: Lathe paint stripping and prep
01-01-2008, 11:32 PM #1
Lathe paint stripping and prep
Hello all. I have a question about removing old paint and cleaning the surface to get ready for new paint. This may be a really dumb question, but will sand blasting or bead blasting damage the ways of the bed? I have access to sand blasting equipment and it seems a fairly rapid and thourough way to get all this paint build up off. I thought I would go over the ways with some sugar sand or glass beads and clean them up, hopefully making the ways look better. I've rubbed pretty vigorously with Scotchbrite and WD-40 and I have them looking a lot better than they were. It seems to me like it might add some slight porosity to the surfaces making them hold oil better than they would if they were shiny and smooth.
Also, has anyone ever used body filler on the compound, saddle or cross slide to get a better looking finish? My compound and cross slide are dinged up in places, and would look quite a bit better if I filled those places in before painting.
01-02-2008, 12:17 AM #2
While others here might have different views on this...I don't think I'd use sand anywhere near a lathe and I don't think I'd be tempted to blast the ways with anything at all including glass beads. While some parts could be cleaned with beads you will have to use some caution --around-- any machined surfaces with pressure abrasives.
I'm sure that isn't what you wanted to hear...we all like shortcuts..I just don't think a blaster is the correct tool for what you want to accomplish.Sand will get into places you don't want it absolutely,that's for sure. Abrasives under pressure can remove metal from areas that were machined for close tolerance fits,which in most cases isn't good.
I've got 3-4 sandblasters and other than non-machined pieces (with glass beads) I don't think I'll be using a blaster for any parts of my lathe(the ways already have enough wear in them).
I'd be interested in others views on this subject as much as you... these are just my thoughts on this. I'm sick of oven cleaners,paint remover & scrapers and dental picks.
01-02-2008, 12:22 AM #3
When I restored my 405, I sandblasted everything, including the bed. I taped/masked the ways to prevent hitting it with the blasting media. I did hit the tailstock way in one small spot and in my opinion, I would not want to do that to the ways in general. It gave that spot a matt finish as you would expect. I would think that you would want the ways a smooth as possible.
I used JB Weld to fill in dings and pitting in my compound and a few voids that showed up in the headstock casting after blasting. Worked fine and looks good.
P.S. I also taped the heck out of any oil passages, bearing surfaces and anywhere else I didn't want sand to go. tmb
Last edited by flathead4; 01-02-2008 at 12:24 AM. Reason: more info
01-02-2008, 12:24 AM #4
Do a search of this forum and you will find a number of postings that will provide answers to your questions.
I use Mr. Muscle oven cleaner as a paint stripper.... I would not use it (or any oven cleaner) on the parts (gear covers/doors, collet tray, etc.) made of aluminum, though.
Body filler, JB Weld have been used as fillers. There are also filler primers that can be used. Where the castings are not course, a polyester spotting putty over the primed surface can be used.
I wouldn't do any sandblasting unless the machined surfaces (precision or otherwise) were super-protected from the blasting media hitting it.
01-02-2008, 12:42 AM #5
i would not use sand blasting or bead blasting unless i were to dissasemble the whole lathe. like others have said the blasting media gets into everything. also do not use a pressure washer as there are no seals on these lathes and the water gets into the spindle and gear shafts and pits everything. if after dissasembling everything and you want to sand or beadblast just do not blast the bed ways. it will erode the surface and accelerate wear on the saddle and ways.
01-02-2008, 12:51 AM #6
Ok. I sure appreciate all the comments. I knew it would frost the surface, but I was not sure if it would take any metal away. So now I know not to try that. I don't want to be the experiment that failed. :-) The bed is what I was mainly going to sandblast. I wasn't going to try that on the headstock...not unless I had it completely disassembled. I will go with the tried and true cleaners (and the dental pics).
One restoration I read about, the guy used a turkey frying pot with a propane burner and used a solution called TSP or TPS or something like that. Not sure if he boiled it or not, but he heated it and stuck his parts in there for a while and then took them out. At that point he stated that all he had to do was brush off the paint that didn't cook off and clean with water (I believe) and that was it. Sounds like a pretty good method. He even cleaned the bed that way. He had to stick one end at a time in the pot to get it all cooked off. Anyone else heard of this?
01-02-2008, 01:36 AM #7
01-02-2008, 01:43 AM #8
I've heard of people using TSP for this,but nothing about specific methods & my bed needs cleaning badly. Hot dip sounds good since the weather got colder.
My lathe had damage from S&H and then I found a broken gear so it's setting in however many pieces you can tear a SB 9A into all over the shop plus all the extra pieces & tooling I bought too.One headstock wick was FUBAR so I'm glad I dismantled it.
I did the oven cleaner in a plastic bag thing with misc. pieces & wasn't impressed. I used carb cleaner on smaller pieces as well as the headstock with better results. Pipe cleaners are great for oil passages.
It probably wouldn't seem like such a task if weather--the Holidays--materials---parts---as well as other things in general hadn't gotten in the mix to slow things down.I'm putting together a custom desk/stand for it too. Gotta have a place to put it & tooling.
I feel like this is taking too much time...
What would be a reasonable time frame to refurbish(total teardown & rebuild & refinish) a SB 9A considering it's a part time project? I haven't been able to mess with it for a couple of weeks lately.
I don't expect to have as nice a finished project as some I've seen here,but I think it will be presentable when done & hopefully functional as well.I know it will at least be in much better condition than what I started with.
I don't know how much others have invested in their toys,but mines in pieces and even though it was cheap at first + S&H + Damages + new parts + tooling + lots of misc. + irritation... I'm not so sure the ones that already have all the bells & whistles and ready to go aren't the best way to go. Those in the NE or N Central that have access to machines have no idea what can't be found elsewhere in the country... Consider yourselves Very Lucky.(Except when it Snows! LOL) I'll be happy when it's behind me,but right now it's a PITA.
01-02-2008, 02:54 AM #9
Stripping paint grease and grime
Before you get to carried away with commercial paint stripper go down to your local janitorial supply store and see if you can get a can of Mr. Muscle oven cleaner. Now do use good gloves when you use this stuff. Spray a greasy dirty painted part with a good coat and let it sit over night. Now rinse it off with your garden hose out in the drive way. Your going to be amazed at what happens. You may wont to have a stiff brush with you to help loosen all the crud that is going to come off your part. Take the part inside and blow dry quick. After you see what this stuff does you will be using it just like I have for the last 25 years. I purchase it by the case. Its expensive but I have never found anything that works this good this easy.
Word of warning Get the WD-40 out of your shop. You spray that stuff on anything you wont to paint and your going to get fish eye like you wont believe. That stuff is loaded with silicon. In my business or any business were you are manufacturing parts that are painted or powder coated that stuff cant even be in the building. Ask me how I know.
01-02-2008, 04:14 AM #10
I am currently restoring an old 9" hercus, a clone of the Southbend, and am stripping every casting down to bare metal. All parts are being disassembled.
I started off using normal caustic paint stripper, but it dried too quickly. I then switched to another stripper called Citristrip which stays wet and cleans up in water. This works OK but takes too long on large surfaces.
Now I'm using a cupped wire brush in my angle grinder, wow, that really rips the paint off. Paint I can't reach is removed with Citristrip. This combination works really well.
Lightly rusted machined parts, nuts, bolts and washers etc, are given a going over with a brass wire wheel, buffed with grey compound on a sisal buff, then polished to a mirror finish with green compound on a cotton buff.
The results are amazing, the parts look better than new.
I'm using Dulux epoxy etch primer for the undercoat, and Dulux epoxy enamel for the top coats. Machined surfaces containing dings, were filled with a tig welder, then gently filed back to match the surroundings. Rough castings were filled with two pac body filler after priming, then reprimed.
Attached are a few parts I've done so far.
My apologies for the poor quality of the snaps, lost when saved as a small file. The parts, in the flesh, look as new.
Finally, do not sand blast anything, except maybe the metal cabinet, if you have one.
01-02-2008, 08:40 AM #11
I've been using commercial paint stripper (as found in most hardware stores) on nearly every stripping project for years, and find it works very well. My last project was a SB9, and it took only about 1 qt of stripper, followed by about 1 qt of denatured alcohol (aka stove alcohol) to wash off the stripper residue. This method also removes the grease and grim almost instantly. I use a large pan and load it with parts (except for the bed), thoroughly coat the parts, then cover with foil to reduce evaporation. After 20 minutes or so I use various wire brushes to remove the loosened paint, and repeat as necessary. As each part is done it is rinsed with the alcohol (while the srtipper residue is still wet!) and blown dry. This rinse usually requires 2 passes. The first with dirty alcohol, then with fresh. The dirty pass removes the majority of residue, and the second the balance.
I then do a final wash with laquer thinner just before the first coat of primer. Dirty solvents get canned then go to the local recycling center.
This process works very well, but requires plenty of ventilation and protective clothing.
01-02-2008, 11:56 AM #12
Ditto Dennis...couldn't have put it any better.
All I can say is if you want every spec of old paint removed and end up with a"virgin" clean surface, Mr. Muscle is the way to go. If you want to spend hours wire brushing old paint, messing with paint strippers, and altering machined surfaces with sand or bead blasting...then go for it.
There are many threads on this topic. If you are trying to truly restore your machine to factory like condition then Mr. Muscle gets the job done. If you really aren't that fussy but just want a cleaned up appearance, do whatever suits your fancy.
Finally, if you ever get a chance to see Denny's restored lathes you then will appreciate his recommendations.
That's my take on this well documented subject.
01-02-2008, 12:44 PM #13
01-02-2008, 03:08 PM #14
Just of the record, WD-40 does not contain any silicone. I checked their information here: http://www.wd40.com/Brands/wd40_faqs.html
We also don't want it anywhere near any painting operations, it sure does contain some kind of oil, but it doesn't cause the same problems that silicone does. Silicone will indeed cause tremendous fisheye problems, is very difficult to remove and I have seen it contaminate paint surfaces right down to the bare metal.
No silicone lubes are allowed in my shop for these reasons.
01-02-2008, 03:30 PM #15
Silicone contamination is another story, it is very difficult to remove. If silicone gets on any paint or primer you may have to remove everything down to bare metal, and it still may cause problems. If the parts to be painted are fiberglass bigger problems. I've seen fiberglass parts that were splashed with silicone brake fluid cause fisheye paint problems right down to the gel coat.
Best not get any silicone oils anywhere near stuff you want to paint. You don't even want it to get in the air in the shop, it will cause paint problems.
01-02-2008, 05:22 PM #16
01-02-2008, 06:13 PM #17
Oil and grime removal
Hello, don't know if this helps any but there's one cleaner that I didn't see mentioned in the other posts so I'll bring it up here.
For cleaning oily, greasy filth from my antique outboards, I've found nothing better than Castrol "Super Clean", its a citric acid based solvent that is rinsed off with cold water. Even smells "orangey". It will dissolve several types of paint, so it can be used as a paint softener. You can use it at full strength or you can dilute with water. For my applications, its about as good as a product as I've found. Spray it on and rinse it off, or you can help it work through the crud faster by scrubbing with a brush. Follow instructions to the letter, particularly with respect to handling it safely, and there won't be any problems. And it will removes silicone residue, as I've successfully painted many parts that somebody else has gobbed over with silicone or sprayed with some agent containing silicone (wasn't me, I would never do that, hehe). Rinse with Super Clean, throroughly rinse with water, air-dry, then pre-heat before painting is about all the surface prep I do to all my cast iron motor parts before they receive the finish coat.
For the record, the paint I most commonly use is a rust enamel sold in Canadian Tire stores up here in C eh N eh D eh, its called "Armor Coat", and when its dried, its extremely chip resistant and seems to be impervious to gasoline.
Super Clean is sold at most auto stores that sell strippers/cleaners, and Wal-Mart carries it, and that's where I get it at the cheapest price.
Super Clean won't hurt cast iron, steel or brass surfaces with regards to causing actual physical damage. Obviously, since its removing oil residues, it opens up the exposed surfaces to the possibility of rust, so you either paint or protect what you've cleaned right away. It is quite capable of staining or even corroding and/or oxidizing non-ferrous metal surfaces such as zinc or aluminum.
Hope this helps, your actual mileage may vary, no warranty expressed or implied, some settling may have occurred during shipment, local restrictions may apply, void where prohibited.
Chris S eh
Last edited by Outboardguy44; 01-02-2008 at 06:17 PM. Reason: clarification
01-02-2008, 07:34 PM #18
I've repainted at least one machine without bothering to strip the old paint at all, by de-greasing it, filling the chipped areas with Bondo, roughing up a little with sandpaper, and re-priming. This has the advantage that most of the surface filling and preparation has already been done for you. Andy L.
01-02-2008, 10:21 PM #19
The only time I think it would be advisable to do pressure blasting at any time on a lathe or other machine tool would be when it's dissassembled to the bare bed. Best to degrease first then mask the ways themselves with scotch 20 mil tape, the only masking that I feel truly safe with when blasting. As has already been mentioned, no need to blast to clean metal anywhere except the problem spots. Even if it were possible to lightly blast the ways without any dimensional change (which I doubt) you would be imparting a highly abrasive surface onto the ways. Not only that, minute particles of the blast medium will be imbedded in the ways.
01-02-2008, 10:42 PM #20
I have found nothing to compare with TSP. This includes commercial paint strippers and oven cleaners. It also will strip grease and oil probably 25 times faster than a parts cleaner will and works great as a prep for phosphoric acid rust removal.
A strong solution of TSP and boiling water removed a second non factory layer of paint and the original Southbend layer of paint in only a few minutes. Including all filler and grease.
The only issue with the TSP method is the size of the part is limited for most of us, as without boiling the part in solution it is not nearly as effective and fast.
Just my .02