How to media blast a motorcycle frame and swingarm?

[Travlr]

I have a Harbor Freight air compressor.  Specs are 21 gallon - 2.5 hp - 100-125 psi -

https://www.harborfreight.com/air-tools/air-compressors/21-gal-25-hp-125-psi-cast-iron-vertical-air-compressor-61454.html

Question #1: can I use it to strip my motorcycle frame and swing arm?

Questions #2: what accessories should I buy?

Questions #3: what media should I use?

Thanks in advance!

Mike

[Perazzimx14]

A 21 gallon compressor is going to frustrate you as it you'll get about a 20 to 30 blast of air then stop and wait for the compressor to catch up. Then repeat about 4,000 times.  I have access to an industrial media blaster at work with a hicap screw type fast recovery compressor and after about 5 minutes of continuous blasting it needs to catch up. Its also exhausting work holding onto a nozzle jetting out 125+ PSI pressure./media

Save yourself time, money and effort and take it to a shop. For about $100 its well worth it.

[rodekyll]

You need to be able to maintain about 80# minimum, continuous duty, for extended periods of time, through a 3/16 - 5/16 nozzle.  That's a big chore for a home-grade compressor.  I've been lucky over the years begging access to commercial compressors (and in some cases commercial blasting booths) to do this task.  If you know a shop owner and can barter or borrow time on his compressor it would be much kinder on your equipment.

A full frame and swing arm is going to take several hours to strip with a shop-grade compressor.  YOu might want to start by knocking off as much paint as you can with a flapper wheel on an angle grinder or chemically, with aircraft stripper.  It's also going to take a LOT of media.  I try to recover as much grit as I can by building a tent of plastic tarps around the frame and recycling the grit until its too pulverized to be effective.

The results though can be worth the effort.

[Chuck in Indiana]

Question #1: can I use it to strip my motorcycle frame and swing arm?

I'd be surprised.  It'll get hot, make your media wet from condensation, then it'll clog up.

Yes.. you *can* do it. A little at a time. It'll be a total PITA though.

[groundhog105]

I have a Harbor Freight air compressor.  Specs are 21 gallon - 2.5 hp - 100-125 psi -

https://www.harborfreight.com/air-tools/air-compressors/21-gal-25-hp-125-psi-cast-iron-vertical-air-compressor-61454.html

Question #1: can I use it to strip my motorcycle frame and swing arm?

Questions #2: what accessories should I buy?

Questions #3: what media should I use?


Where are you located?  Find a powder coat shop and have them blast it.  Most shops use garnet to blast as prep to coating.  That frame shouldn’t take more than 30 to 45 minutes.

Thanks in advance!

Mike

[wirespokes]

I agree with all that's already been said. I've blasted a few frames and it's messy work. There's a lot more area on a frame to blast than you ever realized. And when you're all done, you'll still find spots you missed.

Be sure to very thoroughly mask and block off all areas that shouldn't get blasted, like swing arm mounts and head tube bearing area.

I heard of a Guzzi that got restored but blew two engines before it was discovered sand had gotten into the frame where the breather connects. Some Guzzis used the frame for part of the breather system. Sand would dislodge, get into the engine through the breather and that would be that!

[Chuck in Indiana]

^^^^^ Pay attention to that last paragraph..

[kirb]

I would mask off the frame and find a shop/guy who has the proper equipment. Make sure you specify the media or he might use very coarse grit that could not be what you are looking for. Finer grit will do less damage, but take longer.

I had my Indian frame and some wheels done by a local guy and was happy with the result, but the wheels were VERY pitted afterward. Not a big deal for the powder coat I was using. Something to think about. Alloys will need more care than steel. Bearing surfaces, threaded areas, or other high-tolerance spots will need to be addressed. 

You could always rent an industrial air compressor for a day or so and not have to worry. A home-sized compressor will take forever and usually doesn't supply enough air to get the job you are looking for. The lines have to be fairly large in diameter to flow the air needed to blast a large part. My compressor (5HP, large tank) does OK for a smaller booth, but it would take me an hour to do pipe 18" long that was covered in paint. I would hate to try a frame hanging outside...that would be a weekend or more of hell. Sand EVERYWHERE.

Blaster with diesel air compressor from my local rental place would be about $200 + media for a day. You should be able to find a shop that can do it for that.

[Travlr]

Thanks guys!  I like the idea of doing it myself, but it sounds like this job is best left to a pro.
I think I'll call my painter and see if he has a recommendation for a good blasting shop.

Mike

[guzzitime]

If you suspend the frame for blasting, ground the thing, or you might get the bejesus knocked out of yourself. Don't ask me how I know.

[jbell]

I did mine with the same model compressor you have.  I used cheap "play" sand from Home Depot.  Use a good filter/dryer in your airline.  It is messy, you'll spray for a very short time and then have to wait for the compressor to get the pressure up again.  After doing it a bit, you'll be able tell when the pressure gets too low.  It, however, can be done but this is not a one afternoon project. Get a cheap blasting hood off the internet and drape an old sheet over yourself, that sand gets everywhere.  Again, tape off any areas you don't want sprayed.  Oh, and be sure to check the oil level in the compressor every now and again.  Degrease any areas that are caked before blasting.

[wirespokes]

If you don't have a blast cabinet big enough, I think I've heard of using an old camping tent. That would keep most of the grit inside and off of you. I've used a big box - like for a refrigerator - and that kept at least 60% of the sand local.

[rodekyll]

It will take a couple or more bags of grit, so the cost will really add up if you don't recover as much as you can.

[jdgretz]

Don't do like Mullet5 did when soda blasting his engine for his Minsk rebuild --> http://advrider.com/index.php?threads/lovingly-restoring-the-worst-bike-ive-ever-ridden.618122/page-5#post-14253267 (still one of the funniest posts I've ever read).

jdg