Drilling f/glass tanks

brother of feeeshpond · Wed May 16, 2007 12:23 pm

I have at last managed to get a large f/glass tank=6ft x 4ft x4ft as a quarantine tank.
Is there any parcicular way of drilling/cutting holes in it to stop it spliiting etc.
Engineering skills with metal=very good
Engineering skills with f/glass= don't know as I have never needed to do it before.
Any advice gratefully received.

haddenhamkoi · Post by **haddenhamkoi** » Wed May 16, 2007 1:21 pm

I have never drilled fibre glass.
But if i was going to, i would place heavy duty tape over both sides and mark the hole on the tape and drill through.
The tape on both sides would help stop it chipping and on the other side stop the fibres tearing away/pushing outwards

dho · Post by **dho** » Wed May 16, 2007 2:12 pm

I don't think that there is any special skills required. Just use a hole cutter and treated as you would plywood. Try to get the hole cutter square on to the surface your are cutting, don't use too much force. In order to get a neat exit hole you can try and clamp/tape a piece of plywood to the other side of tank, so far I haven't even found that necessary.

vippymini · Post by **vippymini** » Wed May 16, 2007 4:05 pm

Ok , you need to treat fiberglass as if your cutting a ceramic tile. Using a jigsaw with a carbide or diamond blade at slow speed whilst not letting it get too hot .

Telthepondman · Post by **Telthepondman** » Wed May 16, 2007 4:08 pm

No special skills required, use a good quality hole cutter, drill from the face and when you are half way thru' or so drill from the inside, this will stop any splitting out and will leave the hole nice and clean from both sides, remember to use a slightly bigger holesaw than the fitting that you intend to pass thru' it Regards Tel.

vippymini · Post by **vippymini** » Wed May 16, 2007 4:20 pm

ther may be no special skills required but a normal run of the mill hole saw will blunt and burn out in a matter of minutes if the fibreglass is made properly. take it slow..

better to spend a couple of quid on a pack of tile blades for your jigsaw than a tennor on a hole saw that youll throw away the same day.

Telthepondman · Post by **Telthepondman** » Wed May 16, 2007 5:23 pm

Well, i would not agree, how you would use a jigsaw to drill a hole say 1" diam for insatnce is new to me. All accuracy would go out of the window in my humble opinion, and you need to be accurate as there is not much cover on the fitting flange.The choice is yours, but i did stress in my post that you would require a quality set of cutters. I have personally never wrecked a good holesaw on a fibreglass tank. Tel.

Dazzle · Post by **Dazzle** » Wed May 16, 2007 6:50 pm

I have used an adjustable hole cutter before. It was a very dangerous tools but did the job a treat.
It was blunt afterwards though!

Whatever you do, put a mask on. The dust is nasty.

GERRY5 · Post by **GERRY5** » Wed May 16, 2007 7:04 pm

have to say i always use a hole saw without any probs. , dont force it though , let the blade do the work and it should be fine

macaws fly · Post by **macaws fly** » Wed May 16, 2007 7:28 pm

well what can i say.
fibreglass when its made properly is mostly glass and very little polyester resin, so its vey tough and will blunt a normal toolsteel drill bit or holesaw very quickly.

as with anything in the world there are different ways of doing things and drilling holes is one of them.
if you want a single hole of under an inch then i would say use the largest drill youve got and file it out to the size you want. if you want a hole three inches then i would use a drill to start and use a tile cutting jigsaw to open it out.

yes you can use a holesaw but do we all have one?

i've worked with fibreglass for about 20 years and over that time i have collected many different tools for cutting and shaping it, the best are the diamond coated tools. they slice through fibreglass like its butter with no wear to the tool.

[img]http://www.made-in-china.com/image/2f1j00sV ... l-Bits.jpg[/img]
holesaws or core drills, the big ones your local hire centre uses them for cutting through concrete.

so what i'm saying is "use what you got" and use a little water to keep the dust to a minimum.

Davej · Post by **Davej** » Wed May 16, 2007 7:54 pm

I haven't had any problems when drilling fibreglass, either in a Fish tank or Boat.

Holesaw will be OK, just make sure you drill in the right spot. Measure, check and measure again.

If U are nervous of breaking out, then depending on location U can clamp a piece of wood against the exit side, if not then simply tape it.

As normal with any drilling, let the drill do the work and there's no need for high speed.

Dave

fatherted · Post by **fatherted** » Wed May 16, 2007 9:13 pm

I cut a 2" pipe hole in my filter with just a hacksaw blade (the plastic cutting type) and no saw / holder.

Dazzle · Post by **Dazzle** » Wed May 16, 2007 9:50 pm

I reckon 'Brother of Feeesh Pond' has cut all his holes by now and we're just chatting about tools and cutting holes amongst ourselves

I cut a loads of 4" holes with an adjustable double blade drill bit I bought cheap off the web. One of the blades came undone, flew off and embedded in my filter house wall!

It could have been worse though given i was working at waist height

.

son of fishpond · Post by **son of fishpond** » Wed May 16, 2007 9:59 pm

Many thanks for all the replies.
Tank will be with me in the morning , so no , I havent started drilling /jigsawing anything yet.
To follow on from this thread which I intend to do, I am going to start a new post.
Titled what do I do to my new q/tank.

brother of feeeshpond · Wed Jun 20, 2007 4:51 pm

Many thanks for all replies
Spent out on a very good 4"hole cutter and mandril---perfect!
Probably use it once more for another job .