Newbe questions on floor and stringer rebuild

[H2OHOII]

Craig -sounds like a man with a plan ! very cool ! would love to see pics !

OK, so here is sort of an off the wall question... what kind of sanders do you folks use ? air sander or grinder with sand disk pad ? obviously there is a compressor needed for the air sander, but does anyone have any preferences ?

[missinginaction]

I'd say the answer depends on what it is that you're sanding or grinding. I've gone through 2 Rigid 5" variable speed sanders and am now using a Dewalt. The Rigid's are guaranteed for life, but who wants to wait for weeks when you have to send them in for warranty repairs. Gotta build when the weather is good, so I just end up buying a replacement. They're only $60-$70 so it's not too bad. These sanders hold up well and you will really abuse them.

When I replaced stringers and needed to attach structural members to the old hull, well, that was different. Then I had to do some serious grinding and I used a 4" angle grinder. BTW, I'd steer clear of belt sanders. The one I bought years ago only gets used when I clamp it to a work bench and use it as a stationary sander. Bought the belt sander before I knew what I was doing. Could have saved some money

So it depends on what you're doing. AN electric 5" random orbit sander worked fine for most finish work, but if you really need to grind some fiberglass for structural work an electric (or air powered, I suppose) grinder is the way to go.

Don't forget to buy a decent dust mask, or better yet respirator. Your lungs will thank you.

MIA

[irv]

Well first I'm not a pro, but have ground alot of glass, wood, metal, even rounded granite and tile. I use an air driven 5" disc sander 16 grit and up aluminum oxide for heavy removal, going up to 200 and more grit for more carefull work. Close flat work where is matters and rounding corners I use a belt sander various grits, wet hand sanding with a block for that last finish. There not to expensive if you buy online.

[PAR]

Pneumatic tools are rebuildable, electric tools can have brushes replaced, maybe bearings, but usually aren't rebuildable. If you use tools enough, you buy what is rebuildable.

When it comes to sanders, there's usually one for each job you'll do and none will last very long if you ask it to do things, it's not well suited to do. The biggest mistake most backyard builders make is using a finishing sander to do stock removal. Everyone seems to think a DA can solve most of their sanding issues, but it's just a finishing tool and not well suited to most sanding tasks. Of all the tools I own, I have many more sanders then anything else, with the possible exception of saws. Some of these sanders only get pulled out every so often, but when it is, it's the only tool to consider for the job I have in mind for it.

[H2OHOII]

gotcha.... makes sense. There is a correct tool for everything.

Now here is a more technical question, that I have wondered for years, but never thought about it at the right time to ask anyone....

What is the main criteria that determines what the max HP outboard motor a boat will handle? This really came to a head yesterday when I saw a 16' john-style boat with a 90hp merc on the back for sale at Bass Pro's... For such a light boat, that just seems like alot of motor! I can see that it's an Aluminum boat and rigid enough to handle, but the overall weight of the boat seems like it would be too much motor.

I know there alot of factors that come in when selecting the right power plant for a boat. Obviously you need enough power based on the weight of a bigger boat so it is not a slug in the water. but what is the cut off limit to say a boat cannot handle any more HP. Take my boat for example, the original motor that came with it was 40hp why would I not be able to put a 60hp on the back ? In looking at the factory docs for the boat, the max was 40hp.

so, as i said, I kind of have always wondered what criteria dictated the max hp for an outbard boat.

[Ike]

It depends. I know, wishy washy answer.

Monohull boats under 20 feet in length are required by law to use formulas published by the USCG (in the USA. Canada and Europe have their own rules but they are the same as the US).

You take the center line length of the boat and multiply it by the maximum transom width. That gives you a factor. The rest is determined by whether the boat has remote steering and a 20 inch transom height. Your bass boat example probably has both. So it's the factor ( L X B) times 2 minus 90. Then round up to the nearest multiple of 5. See http://newboatbuilders.com/pages/hp.html.

For other boats with tiller steering or shorter transoms, or flat bottom hard chine boats, the formula is different, but all are based on length times transom beam.

Now for boats 20 feet and up essentially they can put on what they want, but almost all builders rate the boat based on the American Boat and Yacht Council standard for powering. This requires the manufacturer to conduct a maneuverability test. It is a stndard test course and the boat has to be able to go through it at max speed without any problems. In Europe they use a similar test called collosion avoidance but the principle is the same. if the boat can't get through the course at max speed you have to lower the HP.

[H2OHOII]

Interesting ! thanks Ike