Grind Fest

[mtnrat]

I am going to keep track of how many hours it takes to grind back to the original hull material. Any guesses? The grey stuff needs to be removed. It is poly from an old repair that was poorly done. 18 foot v hull.

 

[klos]

Re: Grind Fest

8 hours?

 

[bassboy1]

Re: Grind Fest

Now what will you give the closest guesser? My guess is 5 hours 37 mins. And 58 seconds.

 

[Bondo]

Re: Grind Fest

Does this include the Time spent in a Cool Shower getting All that Stuff off your Itching Skin,..??..??.......d

 

[mtnrat]

Re: Grind Fest

I think It is going to be around 12 hours. there are some very thick areas around the stringers. I think tose who did the previous repair just poured the extra poly where ever they wanted. Got one of these bad boys. Much faster than sanding disks. Have used it for 2 hours straight and still kicks. Tool guy sad it should last the whole job. Yep the shower and bath is in full use.

Wet spots show up when not expected.

 

[strizzy]

Re: Grind Fest

Flap discs are the only way to go.

I'll take 6hrs for $50.

 

[Tail_Gunner]

Re: Grind Fest

8) Get yourself some 60 grit sand paper 6" adapter and maybe 3 hours ..................maybe.......... 60 will make that look feeble, along with that it will conform to your hull cuts like a laser and anything short of steel wont even slow it down............ ohh and as long as you let it cut the surface will be like glass smooth as glass.

Everything is at home depot, maybe 25 for everything

 

[tashasdaddy]

Re: Grind Fest

i keep both in my arsenal.

 

[Flukinicehole]

Re: Grind Fest

Depends on when its done. On a saturday about 14hrs. including beer breaks or 6hrs during the week after work. Everything takes longer on the weekends.

 

[mtnrat]

Re: Grind Fest

Been working on and off through the winter. Got most of the poly resin ground away. I have found what I think is some mat and fibers that were added on top of the original layup?

The second pic shows what can be seen of the weave of the original layup?

In the third pic I found what I believe not to be original material delaminating, before I lifted it up with the screwdriver.

Does this look like part of the old "repair"? It seems to me that the fibres were added after as they are visable along the stringer location and thickest right beside the stringer.
What do you guys think as my inclination is to grind this stuff away too?

 

[sc_shane]

Re: Grind Fest

I'm looking at that and am going to go with 21 hours. That's a big job and it looks like you're doing it right. Keep up the good work!

 

[mtnrat]

Re: Grind Fest

My first post was back in October. I no longer care about the grind time. The mottled grey is what is left of the poly resin. I now an trying to ascertain whether the glass fibers are original or not.
Here is the "flap" of fiberglass

Here is a close up

Here is the top side of "flap"

Here is an area where it looks like stuff similar to the "flap" overlays the original layup

And here is another spot where I can stick a screwdriver into the offending material along the chine where it was built up at the front end of the stringer..

 

[mtnrat]

Re: Grind Fest

Can anybody help me to identify this material as repair or original. I hope to get after it this weekend.
I added to my original thread for continuity. I hope that was correct rather than starting another thread. I intend to add pics as this project continues, through stringer, floor replacement, bottom fairing and paint.
Thanks,
Sean

 

[ondarvr]

Re: Grind Fest

It's very hard to tell from the pics whether it was built that way (poor job) to start with, or it's just a bad repair.

If you go deeper and find layups that look different and are in good shape, then it's just a bad repair job.

 

[mtnrat]

Re: Grind Fest

Thanks

 

[Yacht Dr.]

Re: Grind Fest

mtnrat, could you in one of your next set of pix do me a favor. wipe the chine with acetone just before you take the pic. I could see alot better whats underneath those repairs a whole lot better that way. thx

YD

 

[mtnrat]

Re: Grind Fest

I hope this is better. The black circle indicates where the "flap" was and underneath looks like the original layup. The area within the white lines is the offending material that looks to be a mix of fibers and resin applied on top of the original weave of the layup? You can see exposed fibers along where a stringer is located.

 

[Robj]

Re: Grind Fest

Mntrat,

I tried your flap discs, my 24 grit standard disc has much more of a bite. The flap disc is good for finish sanding prior to glassing, but the 24 grit disc is better for material removal.