removal of old antifoul....???

[Elessar]

Our Hardy is now 10 years young. Last couple of lay ups I wet sanded just to key up old antifoul for fresh coat, but just toying with the idea when the boat is lifted in December of doing a rather more substantial rub down to get the build up of a decade of antifoul layers down to a thinner layer....

Complete waste of time? or a worth while job....

(BTW, Skint at the moment so would not pay for any kind of blasting procedure! it will just be me and my black & decker sander, and a bad back..)

dry blast £312 from us.
Check out the price of intastrip and remember we do a lot of boats that have been 1/3 done by the owner.........

However it doesn't sound like your boat is that bad so you may get another year or 2 before having to do it.

 

[Elessar]

Hi daka, I think you are famed for that view... It is one I share, it really is a very brutal treatment, if its the first step to getting rid of osmosis... then fine... otherwise wouldn't ever want it done on my boat.

I am warming to the chisel idea though... like the idea of nice shiny gelcoat.

Read MBY October 2010 if you want a comparison of all the removal records, blast and non blast, including a picture of DAKA himself.

In it we blast an old sunseeker without 1 single pinhole. Vacuum bagged it would not have been.

pm me if you can't find a copy.

True it needs a good operator (especially a dry blast) but with one it a safe and quick way of getting back to bare.

BTW one thing it isn't is the first step to getting rid of osmosis. A good blast is too gentle to burst the bubbles.

 

[Ripster]

Hi daka, I think you are famed for that view... It is one I share, it really is a very brutal treatment, if its the first step to getting rid of osmosis... then fine... otherwise wouldn't ever want it done on my boat.

I am warming to the chisel idea though... like the idea of nice shiny gelcoat.

If you go the electric chisel route - it will be interesting to know what you think and how long it takes etc.

I thought there was an ice-blasting option now ??? that absolutely does not harm the GC layer - or have I got this wrong?

 

[Elessar]

If you go the electric chisel route - it will be interesting to know what you think and how long it takes etc.

I thought there was an ice-blasting option now ??? that absolutely does not harm the GC layer - or have I got this wrong?

Ice blasting doesnt abrade the gelcoat at all so you usually need to sand afterwards. Its also very expensive.

I looked at offering a dry ice option (we already do dry blasts and farrow blasts) If you buy 25kg of dry ice today there is only 17kg left when it arrives tomorrow. So consumable costs add to overall cost. It is also slower. We just couldnt deliver ther service at a sensible rate so gave up on the idea.

Read the MBY article!

 

[vas]

slightly off topic,
would the el.chisel technique work on a 35yo plywood hull with primer and various layers of A/F? Looks from an earlier poster that it could be ok?
Also chiselling a 40ft+ hull surely takes some time, no?

cheers

V.

 

[maby]

slightly off topic,
would the el.chisel technique work on a 35yo plywood hull with primer and various layers of A/F? Looks from an earlier poster that it could be ok?
Also chiselling a 40ft+ hull surely takes some time, no?

cheers

V.

I see no reason why the electric chisel would not work there either. Look for one with variable speed and a range of blades - they don't have to be particularly expensive - mine cost less than £30 from Aldi a couple of years ago. Get a bit of practice first, either on some scrap wood, or on the keel, before letting it near your gelcoat - or plywood. On mine the corners of the blade were very sharp with a risk of digging in if your hand slipped - round them off on a grind stone if necessary to reduce the risk of accidents.

There's always a trade-off between speed and delicacy, isn't there? When you start, you are going to be slow while you learn the action, otherwise you are going to dig too deep. Once you've learned the action and the amount of pressure you can apply safely, you can pick up some speed. Keep an eye on the state of the blade and sharpen or replace when necessary - if it gets chipped, it will leave scratches and gouges.

 

[vas]

sorry for reviving a 6month old thread, but just had a go with a NON-variable speed el.chisel thingy (EINHELL 50euro delivered) and I'm not impressed much. Bought 2 blades, a short and a longer one and I can definitely say I'm disappointed...

Task is removing 3-4layers of paint off plywood and also 1-2layers of A/F and various undercoat on the plywood hull.

Angle of attack is critical (and I still don't really "have" it...). The short blade is vicious, 1degree more and it digs, one degree less and it does bugger all.
The long blade flexes more and is more forgiving edging to doing bugger all at any angle.

So, not happy, was told to try belt sander but I'm afraid of causing more havoc
seriously considering a 130euro variable speed el.chisel first.

Any opinions, anyone tried in sucessfully in plywood and can share his technique?

cheers

V