Angle Grinder Question

[mrbrownliner]

Hey All,

Total newbie here so sorry if this is a dumb question. I just started my first restoration project on a small skiff. I purchased an angle grinder which came with some wheels. They guy at Lowe's asked me if I wanted wheels for concrete/masonry or steel.... Neither of those option mentioned anything about fiberglass. Does it matter which kind of grinding wheel you use?

Do you use the angle grinder on any surface that you want to get down to good glass or is that just for the ugly spots with bad patching, etc....? In other words are there parts that you use an orbital sander alone or do you grind the whole thing?

Thanks... be gentle.... it's my first time!

Lee

 

[Woodonglass]

Re: Angle Grinder Question

Welcome to iBoats! You do not use any of the wheels that come with the grinder. Here's what you'll need.

4 1/2 " rubber Back up pad and 24 or 36 Grit Resin Coat sanding discs. You can get it all at Harbor Freight or at Lowe's.

Make sure to wear a fully hooded Tyvek Suit, Full Face Respirator, Gloves and Coat yourself with Baby Powder before Suiting up. Shop Vac help keep the dust down but it will clog up A LOT!

 

[81 Checkmate]

Re: Angle Grinder Question

Yup.....just what wood said!

That disk you get with the grinder are made for grinding Metal or welds.....

 

[GWPSR]

Re: Angle Grinder Question

Don't discount the usefulness of flapdisks though. The 36 grit ones are great for heavy work. They're cheap, and even though they wear out or get clogged eventually, you get a lot of mileage for the dollar.

I also used a lot of the cut-off wheels for cutting out stringers and bulkheads.

 

[Woodonglass]

Re: Angle Grinder Question

I've use both the Flap Discs and the Backer Pad/Resin coated discs. My experience has led me to believe the latter is the best bang for the buck and with the use of an old tennis shoe you can unclog the glass off of the discs by grinding on the rubber tennis shoe. Makes em last longer and cut better. But as GWPSR says the Flap Discs can and will get the job done too!

 

[81 Checkmate]

Re: Angle Grinder Question

I to was gona mention the.045 cut-off wheels........But didnt want someone to cut a finger off.

That's what i used to cut my deck and many other things....

 

[classiccat]

Re: Angle Grinder Question

I to was gona mention the.045 cut-off wheels........But didnt want someone to cut a finger off.

That's what i used to cut my deck and many other things....

Post #27 comes to mind (jas was kind enough to post as an image link rather than an inserted image).

 

[GWPSR]

Re: Angle Grinder Question

I to was gona mention the.045 cut-off wheels........But didnt want someone to cut a finger off.

It was actually a circular saw that I cut off a finger with. Seriously. Well the end of it at least. I've had much better luck with the grinder. So far :facepalm:

(And the circ saw was not boat related)

 

[mrbrownliner]

Re: Angle Grinder Question

Welcome to iBoats! You do not use any of the wheels that come with the grinder. Here's what you'll need.

4 1/2 " rubber Back up pad and 24 or 36 Grit Resin Coat sanding discs. You can get it all at Harbor Freight or at Lowe's.

Make sure to wear a fully hooded Tyvek Suit, Full Face Respirator, Gloves and Coat yourself with Baby Powder before Suiting up. Shop Vac help keep the dust down but it will clog up A LOT!

Thanks! That helps a ton.

Lee

 

[mxcobra]

Re: Angle Grinder Question

Im late but harbor fright has the flapper 40 grit disk the cheapest I like them the best...I have tried them all.

 

[mwe-maxxowner]

Re: Angle Grinder Question

I found the flap discs to wear out quickly, but you should definitely get one to try. This topic seems to have a lot of personal preferences. I used the metal wheel that came with the grinder quite a bit in some places. The ability to turn it up on edge and use it helped me get some places I couldn't with the resin coated sanding discs.

 

[Lwarden]

Re: Angle Grinder Question

+1 on the resin discs and the rubber backer pad! the flappers do work ok in a pinch but Ive found the resin disc's do a much better job and if you look around will cost less in the long run. Our HF store didnt have the disc's to match the rubber backer so I went to Home Depot and got mine. If you have a lot of grinding to do be prepared for a ton of fiberglass dust, and it gets everywhere. I'd recommened staying suited up till you have it all vacumed up too, because Ive found the least little bit of dust down your shirt or up your sleeve will make you itch! did me anyways! And 1 more thing, if you duck tape the wrists of the suit, that duct tape will ruin the cuffs just FYI ya cant peel it off without ripping the suit unless you have the heavy Tyvec suit. I used heavy rubber bands on my wrists and that worked out fine.

 

[secondchance22107]

Re: Angle Grinder Question

to any newbie working with grinders...my suggestion is before doing any critical grinding practice first...I have been using grinders for 40 plus years and have seen many grinder accidents...its best to get use to a grinder before using it on your boat these can and will get away from you and can cause damage to yourself or the material you are working on...the grinders can and will get away from you and walk cutting and destroying anything in its path...a grinder and a saw is the two most dangerous tools they make and they have no conscious... so please be aware..i have scars to prove it...

 

[Woodonglass]

Re: Angle Grinder Question

This ^^^ is some very good advice!!! Grinders spin in a clockwise direction normally at around 11,000 rpm. That's extremely fast and powerful. You should always wear Heavy Gloves when using them and always use the top portion of the wheel to do the grinding. the dust will be ejected to the upper right side of the grinder. Placing a shop vac with a wide mouth attachment about a foot away from the grinder at this location can help catch the dust but due to the extreme fine texture of the dust it will clog your vac filter very quickly. You can make a Box filter for your vac to help with this situation made from normal House Air filters.

(Click the Pic Below to Download the PDF File)

View attachment Shop Vac Dust Box.pdf

 

[Mel Taylor]

Re: Angle Grinder Question

to any newbie working with grinders...my suggestion is before doing any critical grinding practice first...I have been using grinders for 40 plus years and have seen many grinder accidents...its best to get use to a grinder before using it on your boat these can and will get away from you and can cause damage to yourself or the material you are working on...the grinders can and will get away from you and walk cutting and destroying anything in its path...a grinder and a saw is the two most dangerous tools they make and they have no conscious... so please be aware..i have scars to prove it...

AMEN! Many years ago I nearly sacrificed the end of my little finger to a grinder. Ripped the flesh loose from the bone and left it dangling by a piece of skin. Luckily the right surgeon was in the ER that day and managed to sew it back on so that I was left with only a minor deformity, a slightly cocked finger nail. I learned a valuable lesson that day, namely that the boss should leave the use of dangerous power tools up to the employees.

 

[Bondo]

Re: Angle Grinder Question

Thanks! That helps a ton.

Lee

Ayuh,.... I agree that the 4.5" angle grinder is a Must Have tool,... 1 that'll Bite ya, if ya let it,...

I've also found, you'll find use for any, 'n every disk ya buy that fits it,....

 

[matt167]

Re: Angle Grinder Question

Yup. The only grinder to stay away is the cheapest ( black handle $9.99 special ) from HF. The bearing housing in the end is plastic and when it fails, it sends plastic projectiles everywhere..

A Cupped wire brush disc will strip a rusty trailer frame quick.
I cut most every panel for my scratch built rat rod with my older ( now burned up ) HF 4" grinder using the 4" cutting discs from HF. They are a very versatile tool.. Somewhere I even saw a sawblade for them.

 

[Woodonglass]

Re: Angle Grinder Question

I don't know of any Saw Blade that's rated for 11,000 rpm!!!! At one time I posted an Adpater from HF for this but have since stopped because of the previous statement. If a carbide tip came off the blade at that velocity....I wouldn't want to be the recipient of it!!!

 

[Bondo]

Re: Angle Grinder Question

I don't know of any Saw Blade that's rated for 11,000 rpm!!!! At one time I posted an Adpater from HF for this but have since stopped because of the previous statement. If a carbide tip came off the blade at that velocity....I wouldn't want to be the recipient of it!!!

Ayuh,.... I've got a set for carvin' wood that's built from chainsaw teeth,... Sir Lancealot,...

Haven't chucked 'em up, 'n tried 'em yet,... oughta be Devastatin',...

I think some under-cut saw blades will fit the arbor too,...

 

[matt167]

Re: Angle Grinder Question

Yea, I actually couldn't believe it when I saw a 4.5" sawblade marked for use with an angle grinder. Not something I would like to try, but if the product exists, someone already has.