hatch

Joseph Shirley · Jun 16, 2009

A Drilled hole and a scroll or a saber saw would do. there are some roto cutters that might work also. A circular saw might be used by some but I don't think I would try it.

Steve Dion · Jun 16, 2009

Are you worried about cutting through any AC or DC wires? Just about anything will do, but I would think that a circular saw would be the easiest to cut straight lines.

I would be sure to put tape over the area to be cut on the inside and out to prevent chipping.

Ron20324 · Jun 16, 2009

Maybe plot the cut on a piece of cardboard, oversized to let the saw slide on it. A circular saw with a masonary blade is less of a hazard and you will get dust instead of flying particles. Cut only deep enough to get the skin off (if you can) so you can see if there's anything "important" underneith.

sailormanbigd · Jun 16, 2009

cut hatch

If it was me, i would use a diamond blade in my jigsaw. A circular saw can take a bite and kickback, and the blade sends out showers of sharp glass chips that hurt-ask me how i know? I put some masking tape on the bottom of my jig saw before cutting to prevent scratching the gelcoat. The diamond bits are alittle hard to find and more money, but last alot longer and worth it in the long run. You can use the bimetal medium sheet metal blades but can only get a short cut before they get real dull (no teeth). Also, the diamond blade doesn't chip as bad as the cerrated blades do. Good luck with the hatch. patrick

sailingdog · Jun 17, 2009

taping the cut line with masking tape can help prevent chipping of the gelcoat. If you have a template, a router is the best way to cut it. If you're cutting freehand, a jigsaw is a good way to do it.

Mike Holibar · Jun 17, 2009

A jigsaw would be adequate as suggested but have a look at the Fein Multimaster n this link. http://www.youtube.com/watch?v=nynD2SfyINU It's about the most useful tool in my kit. Another alternative would be a small angle grinder with diamond cutting wheel, but you need nerves of steel. Good luck,

sailingdog · Jun 17, 2009

while i agree the fein is a good bit of gear, the jigsaw is far more common.

sailormanbigd · Jun 17, 2009

well, the Fein looks cool. Gotta be the best for cuttin up to a wall or other obstruction. I guess it oscilates instead of spinning. Is the tool home depot has out on demo for cleaning grout about the same thing. How much is the Fein? And how is the cost/availability of the different cutters/sanders. Interesting tool i must admit. Probably a few hundred bucks and the $20 or morew for each attachement? Patrick

Ross · Jun 17, 2009

Since you don't say what size hole you wish to cut and how much free space you have around it all of the tools mentioned will serve. I must admit that I have never seen diamond blades for a sabersaw, lots of carbide grit however and they serve well. I have used a sawsall for much of the major cutting which included the removal of the aft half of the cockpit. I trued up the cut with a right angle grinder with sanding disks.

Mike Holibar · Jun 17, 2009

I agree with Sailing dog that jigsaws are much more common, probably because they have been around longer and there are models that are much cheaper than the Fein. Also the jigsaw will cut a radius where the Fein works in straight lines. However the fein is very clean to use compared virtually any other form of cutting, because its oscillation doesn't blow the dust all over the place, and it can cut right into corners and so forth without damaging adjacent materials. Over here Bosch have brought out a cheap imitation, about 1/3 of the price of the Fein. According to those that have tried it, you get less than a third of the performance. It usually comes down to how the power is transmitted from the motor to the blade. In the case of the Fein it is done through a gear and fork system giving a very positive oscillation. Typically in the cheap tools the oscillation is accomplished through a cable attached to the armature which takes the drive through 90 deg thence to a fly weight in a bearing. Then when load is applied the flyweight oscillates the blade up to the point where the load becomes too much, then the blade stalls and the cable tries to knot itself. So you pay a lot less and you get a lot less. Another feature of the fein that I am about to try is the attachment for removing caulking from teak decks.

dvideohd · Jun 17, 2009

alternates

I have two of the "really cheap" - ie, $39 - alternates to the FEIN. For just one job - or a few over the course of the year - I think they are FINE!!!!

But you get what you pay for.. If I were going to be doing "good work" on a regular basis - then I would not skimp... you USUALLY make up the cost difference in quality and - or - performance... So for a random orbit sander, I am happy with a pair of Dewalts.... 5X the cost of the "really cheap ones" - but I save a LOT of time... and it is a LOT - !!!! - easier to use....

There's a place for good tools.. and for really cheap - but reasonable tools...

(Tomorrow I will trim the boat house siding with my $39 "cheapo".... works great... but I won't be using it on the Kitchen rebuild coming up... time to get the FEIN.....)

--jr

Bad Obsession · Jun 17, 2009

I am just trying to figure out what you are cutting a hatch for and where it is going to be. Going away from what the manufacturer did may, or may not be a good idea. There are some areas on a sailboat where it might not be a good idea to cut because they are for support.

AXEL · Jun 18, 2009

I've had very good results cutting thru fiberglass using a Rotozip. Go slow, you may have to change bits a couple of times depending on the size of the hole, but it works great!

Chuckbear · Jun 18, 2009

If you can get your hands on the current issue of Good Old Boat we just did an article on installing a hatch over our main cabin. A jig saw will take forever, use a ton of blades and give you an irregular cut. Use a carbide blade in a power saw or a metal cut off blade to get a good cut and make the job easier. Chuck

sailormanbigd · Jun 18, 2009

Ross, I stand corrected. One carbide jigsaw blade last for a good long time. We used it to cut the extra lip of glass left on the mold before pulling hull on a 23 power boat. A circular saw sends out showers of glass chips and can bite and kickback, i'd stick with the jigsaw.

Chuckbear · Jun 18, 2009

sailormanbigd said:
Ross, I stand corrected. One carbide jigsaw blade last for a good long time. We used it to cut the extra lip of glass left on the mold before pulling hull on a 23 power boat. A circular saw sends out showers of glass chips and can bite and kickback, i'd stick with the jigsaw.

Cutting the lip from a mold and cutting through Fiberglass, gelcoat and core material in a deck is not even close. We have done this many times and never had the saw send out chips of glass although plenty of dust so the underside in the cabin needs to be covered. A saw will kick back in plywood if not used correctly but that does not mean it is not the best tool for the job. But if you need further first hand advise ask around at the working yards in your area and see what they would use. Chuck

Ross · Jun 18, 2009

A 7 1/4 inch circular saw is one of the tools I use to earn a living. They are very safe in skilled hand and deadly in unskilled hands. I built a Bolger/Payson Nymph and did all of the cutting with a circular saw.
My son has nursed men that had the saw kick back and attack their thigh. That is a life threatening injury. You NEVER EVER back up with a circular saw. Let the saw come to a complete stop before you lift it from a cut. The saw is stronger than you are so hold on tight.

sailormanbigd · Jun 18, 2009

Might depend on the blade too. I used a carbide 71/4" circular saw to remove the entire inside of the free Morgan 33. Lots of cutting but the blade was tough and did well. I had eye protection and particle mast but my cheeks and forehead were exsposed to the grinding chips from the saw. I have alot of experience with circular all saws. I don't know the number of teeth on the saw blade, just the standard blade that came with the Milwaulci (sp)saw. Matbe a finer blade would have been better? But it must be carbide though, glass will destroy a plain metal blade in short order.
Yes, the 1/4" lip of the mold is different from cutting through two layers of glass and sandwich plywood, but the wear on the blade is about the same, just in different areas of the blade-whatever.

Hermit Scott · Jun 18, 2009

I would use a circular saw with a metal cutting blade or a 4-1/2" grinder (my favorite tool) with a cutting disc. AND I would carefully tape plastic under the hole you are cutting then vacuum it out then remove the plastic or if you can remove the plastic with out spilling the waste.
I ended up hosing the inside of my boat a couple of times just to get rid of all the fiberglass dust from installing the through hulls.

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