Large boat paint removal...

[BrianW]

Hello Folks,

First things first...

"Yes, I did use the 'Search' function." smile.gif

Learned some good stuff too, and it was well worth the time.

I'm looking at buying a 60' wood boat in the next couple months (I posted here before about this boat) and it will need to be hauled and painted soon. Here's a couple pictures to help out...

http://www.imagestation.com/picture/sraid47/pa3c17d6483f1bf38b4dbadc7eaac4459/fcc3d98d.jpg

http://www.imagestation.com/picture/sraid47/pd23d6188c07caf3e58861226e29f144b/fcc3d988.jpg

Given the various techniques for removing old paint, I'm leaning towards the heat gun/scrapper method. I'd like to use chemicals, but I'm guessing the cost for the stripper would be quite high.

In reading some of the prior discussions here, the subject of using a propane torch was brought up as an alternative to using a heat gun. I'd like to know where to buy a torch, or just what features I should look for while searching for one?

Also, at some point my time does become worth more than my money (but takes awhile, as I'm not exactly rich! smile.gif ) I'd like to have the stripping and repainting completed in about two weeks. If chemicals are the only way to accomplish that time restraint, I might still go that route.

One thing to note, the bottom paint was reported to have been re-done last summer, so I looking at redoing the hull from the waterline up. The top half of the boat needs to be repainted too, but that can wait awhile.

Thanks for all the help so far!

[imported_Conrad]

That's a lot of paint. I have no experience personally, but know that some here in the NW have used a propane weed burner to blister the paint, then scrape/disc sand the residue off.

Make a rough guess of the square footage involved. My personal experience with a heat gun/small torch and 2" blade shows about 12-15 square feet an hour- when you're fresh. It's hard work with some paints, and the daily average would be less. But more heat, perhaps even enough that some wood is lightly scorched, will really speed things up. Then an 8" foam pad and some 36/80 grit could clean up the surface.

[Rocky]

I know we're not supposed to venture opinons unless we're experts, but if it were mine I'd remove the obviously loose paint with a scraper or wire brush and paint over the rest, touch up forever with a spray can. Most of that paint looks pretty good.

[Dave Hadfield]

Get a 5lb propane bottle, 10ft or more of line and a burner nozzle. Then, if you can't find one, take some sheet metal and make a flame spreader that clamps onto the nozzle and squeezes the flame into a fan-pattern. Any sheet metal will do, at least for a while (except aluminum, obviously). You can make one with tinsnips and pliers and trial and error.

Put on a good respirator, protective clothing, melt the paint until it bubbles and scrape away. A sharp scraper is less work. Catch the scrapings in a tarp below. Have a fire extinguisher handy.

It's tedious work but moves faster than you think, and you can instantly see the result -- quite clearly you've DONE something. That's always a nice feeling.

[ 01-18-2003, 12:36 PM: Message edited by: Dave Hadfield ]

[thechemist]

Chemical strippers will cost too much, and will leave *someone* with a hazardous waste disposal problem, for which they will pay good money, and it will eventually come back to you.

Torch it. Heat will be the cleanest and fastest and most economical method over large areas.

There may be small spots such as nooks and crannies that cannot be easily torched or sanded, and for those a chemical stripper may be the best remaining method, but save it for last.

[Allen Foote]

The only "sane" way to remove such a large area of paint is by chemical stripping. When the removed paint strips are dry, they are very brittle and easily picked up with a shop vac. So, a simple drop coth underneath will solve that mess. I use the Marine paint remover from McCormick paints. Most automotive stores such as "Auto Accessaries" carries 1 gallon cans of aircraft paint remover (I beleieve for removing lacquers). Anyway, shop around and don't spend more than $20/ gallon. Buy the most TOXIC & LETHEL remover you can find.....you want this to REMOVE PAINT....not to plant flowers in...so stay away from the lemon-juice-extract-good for the environment junk that doesn't work. Follow ALL directions. Let some one else with a smaller boat enjoy HOURS of heat gun experience....use chemicals and get the paint off. :D

[ 01-18-2003, 02:16 PM: Message edited by: Allen Foote ]

[Concordia..41]

Ahhh - don't ya' just love a WBF concensus :D

The heat and scrape method worked well for us removing bottom paint, varnish, and the 40+ years of paint on the coach roof, but the paint on our topsides and cabin sides is so worn and oxidized that it's not thick enough to build up the heat necessary to bubble and sucessfully scrape.

Therefore the next purchase on our tool horizon:

http://www.amazon.com/exec/obidos/tg/stores/detail/glance/-/hi/B0 000223PI/qid%3D949780909/103-2840047-4291056 (http://www.amazon.com/exec/obidos/tg/stores/detail/glance/-/hi/B0000223PI/qid%3D949780909/103-2840047-4291056)

Amazon's price is high, but the Woodworkers Supply site ($395) is down at the moment.

[ 01-18-2003, 03:30 PM: Message edited by: Concordia..41 ]

[On Vacation]

Oh no MARGO, you are all wrong. Put the boat up in the woods for a year or two. Isn't that what you have found to be the easiest in your vast experience here on this community of the Wooden Boat Forum? ;)

[Concordia..41]

Ah Mike, so true. :D

I guess I should have mentioned that I am employing the "just let it sit there long enough and it'll fall off" approach on a couple of other projects.

This just seemed a good opportunity to justify a new power tool, which I thought was WBF commandment #4 (or maybe #6).

Rereading Brian's original post, though I think we can all agree that there's one way and one way only to strip and paint a 60' boat in two weeks and that's:

http://www.nationalbankoftennessee.com/images/man_checkbook.jpg

Regards -

[Rocky]

$530?!

[JimJ]

Have a look at blasting with dry ice or bi-card.

The dry ice method will only leave the paint residue to dispose of where the bi-carb method will have the bi-carb powder included.

http://www.blastermaster.net/sodablasting.htm
http://www.sideline-equipment.com/soda.html

http://www.cryogenesis-usa.com/
http://www.metalstrip.com.au/metalstrip_dib.html

[imported_Conrad]

I have a friend who helps engineer the ice blasting machines- they work well, we've used them on auto engine compartments and other areas where masking is tough. They offer precise control. But the ones I've seen wouldn't be cheap to use, and are slow.

Looks to me like you've got about 800 square feet from what I remember of your boat. A gallon of Air Craft Paint Remover, good for epoxy, urethanes, etc. costs about $15/gallon in bulk, and works an area of 20-30 square feet depending on the paint type. Figure $400-500 for materials, and it won't get it all.

From what I've seen, a 5 gallon/20lb. propane bottle with a weed burner and two guys working would probably allow you to do the whole job in three or four days and cost less than $100. You could probably even rent the weed burner torch head.

I'd try a bit of each technique and see what seems to work best with the type and thickness of paint on the hull, as in my experience the differences can be significant, and you don't know what's best for your situation without a bit of experimentation. Most strippers, for example, work very poorly in cool/cold temps, so they could be even less effective than originally thought.

[tjdono]

What about the portable sandblasters I have seen in the boatyards around here? I believe they use crushed walnut shells to be enviromentally safe. Might be a bit pricey, but I am one who always weighs the cost benefits to the time involved.

Tim

[John E Hardiman]

Originally posted by tjdono:
I believe they use crushed walnut shells to be enviromentally safe. TimThe blast medium is not the problem here. Lead paint or cupric bottom paint or TBT removed is still the hazardious material, not the blast grit. I'm not going to point out how many state and federal laws can be broken by throwing away that piece of bottom paint clogged 60 grit ( part of an "industrial waste stream") in your trash can. :rolleyes:

Walnut shells are used because they don't damage the material as bad as sand (abrasive), glass beads (work hardening), soda blast (wet and rust so paint won't stick), or ice blast (gouges) and they can be seperated and reused easily from the toxic waste (i.e. the removed paint). Each bast material is for a specific reason on a given material. I don't think I'd ever blast on a wood hull for a number of resons, most of which is damage to the planking.

(edited to correct an omission)

[ 01-19-2003, 06:33 PM: Message edited by: John E Hardiman ]

[Dave Hadfield]

I forgot to mention that I recommended a torch over chemical stripper because I tried both. I was stripping 40 years of paint from the 2 masts of my ketch. It was a good test case. They were in my shop and I tried a number of strippers, caking it on thick, keeping it wet; everything I could think of to make it work, but the simple propane torch was much simpler and more effective.

I can only relate what happened to me, but my next topside paint job will involve stripping by torch, not chemicals.

[David N.]

The boat will be hauled out in Sitka ?? , in Januray !! , in the winter ?? .

Many people spend month's prepping the top-sides prior to a haul out , some use moveable dock's , other's work off the dock , some even have those little boat's called painter's !! . Sand , prime and glaze , over and over , that way the haul out is not so much of a shock on the boat , or the help or the pocket book . Lay day's cost x amount of $$$ , and what if the weather is not painting weather , it is Alaska in the winter . You would want what 4 coat's of primer ( plus glazing ) and three top-coat's .

I'am sure you can find plenty to do untill it is summer , and by then the top-sides will be prepped . And I know people that say it takes 4-6 yr's to fair out a hull after taking it down to bare wood . This formula has worked well for many of my friends and some of their boat's are woodies in the 60' range .

2-3 week's staight shot up against the hull , it becomes work after the first morning and I dont care how many promise's you get , it will be lonely on day two .And as far as the bottom goes paint it , it is a must ( IMO ) you need to not take this for granted , you prep and inspect , take photos and make note's , check the plug's , bleeder's etc., strut's , shaft log , rudder(s) , prop(s) , zinc's , thru hull fitting's , and valves . It is what float's your boat !! .

[BrianW]

Thanks to all, for the helpful advice!

I understand that it's possible to get two different opinions, and neither one is incorrect.

The paint on this boat is actually sort of the 'thin' side, compared to some of the other older wooden boats in the harbor. That fact may lead to just sanding the loose stuff, and repainting over the rest. Would it be fair to say, that the heat method works better on thicker layers (or multiple layers) of paint?

The orbital sander pointed out above looks good for that sort of work. Did it work?

As far as the haul out. Well yes, it will be in the winter, at least long enough for a survey. Without checking the Weather Channel, I'd be willing to bet Sitka is a lot warmer than Montana right now. smile.gif Our temperatures are ranging in the mid-30's to low-40's these days. All the snow has melted, and bears have already been spotted out and about.

However, if there are special concerns over hauling in the winter, I'd sure like to hear them! Actually, I'd like to hear any haul out tips, but I'll do a search here before I ask about that subject.

Thanks again to all...

[Nicholas Carey]

Originally posted by BW:
I understand that it's possible to get two different opinions, and neither one is incorrect.

The paint on this boat is actually sort of the 'thin' side, compared to some of the other older wooden boats in the harbor. That fact may lead to just sanding the loose stuff, and repainting over the rest. Would it be fair to say, that the heat method works better on thicker layers (or multiple layers) of paint?I think heat works better regardless of film thickness.

Wood a square yard or so with a propane torch with flame spreader and a scraper. Do the same with chemical stripper.

Which took less time?
Which cost less?
Which was more pleasant?
Which was easier to clean up?

Therein lies your answer.

[and, BTW, you'll find it's the torch smile.gif ]

And...don't forget that if you use chemical strippers, you're going to have to neutralize the stuff, or at very least wash the stripper residue off with water. And that add time to the project and [yet more] hazardous waste to deal with.


The orbital sander pointed out above looks good for that sort of work.The random orbital on the boat hull is liable to put grooves in the hull unless you've got a lot of experience operating one -- don't forget that if you're wooding the hull with a sander, you're probably going to be driving pretty coarse disks to get the paint off (36-grit?). A little different than scuffing paint between coats.

If you're going to sand the stuff off with power tools, get one of these puppies:

http://www.toolsunlimited.com/images/products/V100.jpg

the air-powered straight-line sander (aka jitterbug or air file):

And if you thought chemical stripper was nasty, wait until you try breathing a cloud of toxic paint dust (especially bottom paint.)

[imported_Conrad]

My experience has shown that chemical strippers are worthless at less than about 55 degrees, and operate at that temperature with less than half the speed/effectiveness you'll get at 65-70 degrees.

The heat works better with thick paint, but will still probably be your best bet.

Forget the D/A (dual action) sander as well as the air file Nick has pictured. Both are way too slow for a project of your size and nature where a yacht grade finish isn't required. What you want is an 8" foam pad with stickit paper, probably 40-80 grit and a Porter Cable or Makita variable speed sander/polisher run at 1500-2000 rpm. Do not try it with a grinder and its higher speed!!

When hauling in the winter, remember you've lost the heat of the water for the lower hull- any hoses with water in them and bilge water will now freeze.

[Scott Rosen]

My oh my, that's a lot of boat for one guy to paint. Judging by the picture, you don't need to strip the topsides to bare wood. Usually stripping is only called for when the paint gets too thick or when it peels off in sheets. You've got some spots peeling, but the adhesion looks generally okay.

I'd go at it with a random orbital sander, with 120 grit disks and a dust collector. First scrape the loose sections, then feather in where the paint line ends, then prime the bare spots. After that, I'd give the entire hull a light once-over with the 120 grit. For applying the paint, I'd find a friend and use the roll and tip method. Given the not-so-fairness of that hull, I think a flat finish, or at most a semi-gloss, is called for.

[Donn]

:D

[Nicholas Carey]

Sitka's warmer than you thinks...a lot damper too :( Not too much danger from frost:

</font><blockquote>code:</font><hr /><pre style="font-size:x-small; font-family: fixed;"> Sitka, AK | Kalispell, MT
----------------------+----------------------
Avg Temp Max Temp | Avg Temp Max Temp
------------ ---------+ ------------ --------
Mon Hi Lo Mean Hi Lo | Hi Lo Mean Hi Lo
--- --- --- ---- --- ----+ --- --- ---- --- ---
Jan 39 31 35 59 0 | 29 14 21 56 -38
Feb 41 32 36 61 1 | 35 18 27 64 -36
Mar 44 33 38 59 4 | 45 25 35 72 -29
Apr 49 37 43 76 22 | 56 31 43 85 -8
May 53 42 47 82 23 | 65 38 51 95 17
Jun 58 47 52 85 23 | 72 44 58 96 28
Jul 61 52 56 88 23 | 80 47 64 104 31
Aug 62 52 57 84 23 | 81 46 63 105 8
Sep 58 48 53 77 23 | 69 37 53 99 7
Oct 51 42 46 68 20 | 55 28 42 86 -4
Nov 44 35 39 65 2 | 39 23 31 65 -28
Dec 40 32 36 59 1 | 30 16 23 58 -35</pre>[/QUOTE]

[David N.]

Brian ,

I forgot to add nice looking boat , I'am jealous .

Sound's like you will get a haul-out for the survey , if it was me I would paint the bottom and the boot strap , and work on the top-side's for 6 month's . No matter how you will do it , it is all work , if you have air , air tool's ( and if they fall in the water , you can hose them off and oil them good , they will be ok ?? ) if not , then more than likely you will try all the method's . When hand sanding , tape your finger tip's up , it is a drag to not have any meat left on them !! . I get tired of welding so I learned how to paint , there is one of my paint job's in your neck of the wood's , the boat is a 32' Aluminum cat we built , it is owned by the guy who own's the big hotel up there ( Ron R. ) , I did that boat about 8 yr's ago , it was a real dark blue , and , (then) it looked sweet . Yes I would like to know if the paint is still on the boat ?? .
BOL david n.

30's-40's , tee shirt weather , it is not bad here , you just have to wear everything you own !! .

Heard the price of fish has tanked ( .68 cent's a lb for red's , well , good time to buy a boat . Wonder if the goverment will do another buy out ?? on permit's ?? . I do miss Ak. , the inside passage , what a place !! .

[BrianW]

Gents,

Once again, thank for the advice!

I think I'm getting a handle on this situation. By that, I mean that I think I will scrape the loose stuff, then sand everything down, and repaint.

I'm getting the idea that the orbital sander may be a bit on the small side, and require an experienced touch. A larger sander, as suggested by Conrad, sounds like a good idea. Just enough to feather the edges and scuff the rest of the paint. Then repaint the whole bottom.

When time comes to completely strip (perhaps the topside first, as it's not quite as nice as it looks in the pictures) I'll probably use the torch method, as it's cheaper and there's fewer chemicals to deal with.

I'd lean more towards chemicals if I lived in a warmer location.

This boat is for a charter business (hunting and fishing), not for pleasure. Although I hope to gleam some pleasure from this business! smile.gif I know it's not like some of the gorgeous boats, that I've seen posted here, and that not all of the tips and techniques will apply. Still, I'm learning alot of great stuff, and appreciate all the advice.

[Pekka Huhta]

One thing still unmentioned is an effective infrared heater. It heats just the surface so damaging the wood is not that easy. A relatively small IR heater on a stand leaves your both hands for scraping.

Heats up quick, does a large surface at one time and is FAST. You don't have to scrape one playcard-size spot at a time, you can take long sweeps with both hands on the tool.

Pekka

[Chris Coose]

An 1.5" red devil paint scraper, a bastard file to sharpen it, a dual action 5 or 6" sander and plenty of 100 and 150 disks.

I harken back to the days when I would remove lots and lots of well stuck paint and wonder what I was thinking.

[pcford]

The only method that has any hope of fitting into the owner's time window (two weeks, if I recall correctly)is to sand the existing finish off in a disk sander/grinder. Probably 60 grit would be appropriate in this case.

The other methods suggested, burning and sanding with a air file or DA are hopelessly too slow. Sanding progresses in relation to the speed of the grit particle across the work surface. In a vibrator sander the speed is 4 miles and hour. In a belt sander about 12. In a disk sander over a hundred miles an hour. The relationship of these numbers is the relative time it would take to do the work with the respective tools.

Paint removal has to be done carefully; it is easy to destroy the surface. On a hull with thin planking it is possible to punch right through. But I've used it to sand mahogany speedboats which have hull planking of 3/8 inch. I did (I'm a professional boatbuilder with thirty years of experience) Miss America VIII. That historic boat was a 30 ft.Garwood raceboat circa 1929; it was the first boat to go over 100 miles an hour. It won accolades at the Tahoe boat show. It could be argued that the Tahoe show has the highest standards in the country.

Disk sanding is a natural for this boat.

[LAGOS]

Brian,

I am not hijacking the post, but this my be helpful.

I assume you are familiar with the Jones Act. If not, you need to make sure the boat was built in the United States and is documented by the Coast Guard verifying it's builder. In order for any one to be involved in "Coastwise trade" in U.S. waters, your boat needs to have a U.S. hull. Sorry for the change in topic, Just thought it was important to mention. Would not want anyone to spend their hard earned money on something they may not be able to use.

[BrianW]

LAGO,

No problem with the tip.

I'll double check, but I'm fairly sure she's documented, as the boat been chartered before.

Here's a quick blurb from the survey...

HULL is double-planed mahogany with one 3/8-inch layer and one 3/4-inch layer; FRAMING is 1-1/2 X 4-inch sawn oak, 24-inches on center interspersed with 1-1/2 X 1-1/4 bent oak 8-inches on center; TRUSSES are transverse 1-1/2 X 3-1/2 12-inches on center. Eight watertight bulkheads; two ironbark guards.
"The vessel is a converted U.S. Navy sub or torpedo chaser, of double-planked wood construction, with a raked stem with flare, a round bilge, shallow keel, a rounded transom stern, and a flat sheer. The date of the conversion is unknown, but a full main cabin with raised pilothouse has been added, resulting in a comfortable yacht of good overall appearance with comfortable accommodations."
- 3/8/00 Survey

...I probably should have posted that at the beginning. Sorry.

[BrianW]

Gents,

I'm trying to discern the different sanding techniques that have been discussed. It seems that either a disk sander, or a 'sander/polisher' would be the fastest way to prep the hull.

Here's one quote which caught my eye...


What you want is an 8" foam pad with stickit paper, probably 40-80 grit and a Porter Cable or Makita variable speed sander/polisher run at 1500-2000 rpm.and the other quote...


In a vibrator sander the speed is 4 miles and hour. In a belt sander about 12. In a disk sander over a hundred miles an hour. The relationship of these numbers is the relative time it would take to do the work with the respective tools.Are these two sanders the same thing? Or, is the 'sander/polisher' a lower speed unit?

Thanks!

[LAGOS]

Brian,

It appears your have met the test of the aforementioned statute. Good Luck.

On point with your post, avoid wooding the hull until you need to refasten or recaulk the hull. Scott has the right idea. Address the areas that are bare or flaking, then sand and repaint.

[pcford]

Brian,
I'm sorry, I understand your confusion.

The initial sanding should be done with a high speed (6k or more) sander/grinder. The Black and Decker Wildcat series is an example. The paper has a class C backing. The disk is held onto the hard backing pad with a nut. About 60 grit to start, you might have to go more coarse. Move the disk as flat to the surface as possible. This will remove the paint. And fast-I'd guess one guy ought to be able to do your boat in a couple days. (Never done a boat that big myself)

After you have the paint stripped, you proceed with the softpad. The soft pad is used, as was suggested on a polisher turning at around 1500 rpm. The paper is held on with stickum. The soft pad really is not too effective on stripping because going through the paint generates heat and this loosens the disk. If you use a grit strong enough to be effective, it would be so stiff that it would obviate the advantage of the soft pad. Now, if your old paint is very thin and chalky---it might be possible to use a soft pad. Otherwise use a hard disk. However, the reason people remove paint is that it is usually thick and having adhesion problems

Probably sand with 80 and 120 grit. Finer if you are going for a high finish. Then proceed to fairing and glazing putty.

If you are going for a high finish you will have to make acquaintance with a hand powered long board.

But my guess is that a real high finish is not desired here.

Hope that helps.

[imported_Conrad]

What PC says is true if you want to wood the entire hull, but may not be neccessary here. It also carries the additional risk of doing some real damage if you're unexperienced, tired, or happen to slip! The high speed grinders need to be held so that only a small portion of the total disc area is in contact with the surface being stripped, where the foam pads can be held nearly flat, making it much less likely that you'll cause the edge to dig in and gouge (say up to 1/2" in a wink) the wood. Since your hull is cedar, and very soft, I would carefully consider whether you want the risk. Surprisingly, since the foam pad has so much more of its' surface in contact, the work progresses nearly as quickly with much less skill and concentration required.

I've used both approaches to strip cars and boats, and feel the soft pad is the only way to go. Another consideration is tool weight and your ability to control it. A Makita sander/polisher weighs about half what the average commercial grinder does- how many hours will you be spending sweeping the tool over the surface? ;) If you want to wood the entire topsides, go back to the torch approach.

We use Norton brand discs (Norton Blue) having found them to be the best value, in grits from 36 to 150 and have never had them fly off the pad, even when stripping trucks on hot summer days. I might add that modern car paints are much, much harder to strip than any boat in terms of heat build-up and paper wear. And where you're working it's cool enough that none of this will ever be an issue.

As an aside, D/A sanders are usually 5-6" in diamater, vibrate in 3/16" to 3/8" orbits, and are for finish sanding with grits at 80 and above, best with stuff in the 220+ range. Jitter-bug sanders are the same, except the pads are rectangular, say 3 X 5", again for finishing. Piston air files have a surface 2 X 15", and go back and forth, usually about 3/4" very rapidly. They are for flattening surfaces, and are not only very slow, but run through a lot of paper since only two sides of the abrassive (front and back, never the sides) are used. An orbital air file is manufactured by Hutchins, is very fast, and a wonderful tool, but expensive at $300.

Have fun!! :D

[pcford]

&lt;snips&gt;
What PC says is true if you want to wood the entire hull, but may not be neccessary here. A point well taken. It's really not possible to asess this from the picture. Furthermore, I would look at bare spots to see if there is rot involved. Looks suspicious.
The high speed grinders need
to be held so that only a small portion of the total disc area is in contact with the surface being stripped, Actually the hard disks have to be held very flat or they will dig in as noted.
Another consideration is tool weight
and your ability to control it. A Makita sander/polisher weighs about half what the average commercial grinder does- how many hours will you be spending sweeping the tool over the surface? Don't like Makita disk sanders. They seem wussy and poorly built. (Like pretty much all Japanese hand power tools. Don't care for them. Now Japanese hand tools, chisels
planes and the like--that's quite another thing.)The drive train sounds like a toy. The Black and Decker (or a similar tool) is heavier to be sure. But it is so much more powerful. I would have no doubt that you would be done much quicker.
I might add that modern car paints are much, much harder to strip
than any boat in terms of heat build-up and paper wear. Aren't boat paints much thicker?
And where you're working it's cool enough that none of this will ever be an issue. The ambient temperature won't have much to do with the disk/paper interface.

There was a guy around here (Seattle, his name was Dudley Davidson) that first used the hard and soft disk techique.
He did a great job and much quicker than any other method. He flew to the Great Lakes area to
sand boats. (I can imagine him on a plane with his Black and Decker stowed in the overhead and biceps the size of an Irish girl's thighs sitting next to a besuited exec type.) He sanded away, in a cloud of dust, singing operatic arias.

[John Blazy]

The most obvious way hasn't been suggested yet, but Dave Hadfield came closest. Go buy a portable propane torpedo heater, handheld for less than a couple hundred bucks. That will work right off the shelf, and quickly. Follow up with the 2000 rpm 8" foam pad 80 grit and yer ready for primer. PCford is the closest to correct if not heating off the paint first. I did a whole house that way years ago, but used metal discs with tungsten carbide chips brazed on at about 24 to 36 grit. These were reusable - when clogged, just soak 'em in toluene and wire wheel the paint off. - JB