MFG Gypsy 15 Tri-Hull Restore advice needed

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Ignorance - a lack of knowledge, stupidity - the inability to use knowledge.

I'm using a Ryobi Hand grinder with a 4", 1/4" thick grinding wheel. Using it mainly for "scuffing up" and removing imperfections in the old glass. You can also get "Cut-off" wheels which are about 1/16" thick to cut areas (like along the edges of the floor) with. Because they are so thin and easier to break, Cut-off wheels can be dangerous. ALWAYS WEAR SAFETY GLASSES WHILE GRINDING!

In grinding fiberglass, being careful is the thing. Fiberglass is relatively soft compared to metal and it doesn't take much pressure to do the job. The weight of the grinder itself is sufficient to do the work. There are 2 things to keep in mind about the grinding itself. The face of the grinding disc cuts slower due to the larger surface area. The edge of the disc cuts much faster because it has the smallest surface area and highest rpm at the outside edge of the disc. It's the edge of the disc that can get you in trouble real quick.

Practicing on a scrap piece of fiberglass or piece of wood should give you an idea of how it feels and differences between using the face and the edge of the disc. Fiberglass will cut a little faster than wood.

I also highly recommend you read the Sticky at the top of the Restoration and Building thread related to Grinding Safety.

Almost forgot. If you're going to be purchasing a grinder and other power tools for fiberglass work, don't buy the best you can find! Buy the cheaper mid-grade tools. Fiberglass tears up bearings and brushes eventually. It's better to burn up a $60 tool that does the same job as a $120 tool!

 

[Ezrider_92356]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

i have used the flapper style disks on my grinder a lot. i started out with the cut off wheels and griding disks till i found the flapper disks. i find them to be a little more controllable and work very quick. they also are very nice when your getting ready to glass to rough up a large area. i like them a bit better after they are worn some but they last a very long time, i'm only on my second disk and im done with all the griding part of my transom/floor/stringer job.

 

[newbie_owner]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Question for you Driven1,

Since you are not doing the foam job and going with stringers, are you still going to add some foam for floataion? if so how much?

Thanks

 

[Andy in NY]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Question for you Driven1,

Since you are not doing the foam job and going with stringers, are you still going to add some foam for floataion? if so how much?

Thanks

here:

As promised, here 'tis. The Foam Estimate. Because of the odd shape of the hull it was going to be very hard through stanndard tape measurements to figure out how much foam was going to be needed.

I took Mark42's idea of filling it with water and see how many gallons it took.

The theory was to level the boat front to back and side to side and fill it with water, taking an initial reading of my water meter, and then another when the boat was full. Subtract the difference in readings and then convert the result to Cubic Feet.

The water meter readings and their results worked fine. The leveling theory didn't turn out as I had expected. So, in retrospect, it's best to have three points of level adjustment available AS YOU'RE DOING THE FILLING, one at the tounge of the trailer, and one on each axle. To get what I felt would be acceptable results for the foam estimate I had to re-adjust the boat a couple of times.

The results. The boat took 122 gals to fill to floor level, leaving just a small area in the bow that would not get measured. So I over-estimated to 130 gals and then used an online converter to get the square footage.

122 gal(US Liq) = 16.3090 ft? - That works out to just a little over a cubic foot per the lenght of the boat. Don't know if you could use that as a rule of thumb or not, but thought I'd throw it out there for use in MFG Gypsy's.

So I would need one of US Composites FOAM-0480 80 LB Kits which covers 20 Cubic Feet at $244.00.
This is also a good time to look under the boat for any leaks that couldn't be seen. Luckily my hull's dry as a bone underneath.

Unfortunately for me right now, The foam job's gonna have to wait. I'm going to go ahead and do a standard stringer/floor replacement with a lean towards foaming later.

Sorry guys. I know there were some of you who were really very interested in seeing the foam job done. I was too. I'm laid off and running on unemployment so the cost of the foam is just undoable at the moment. Too big a chunk-o-cash to dump all at once. Damn this economy! IF something changes where I can afford it I'll go ahead with the foaming plans.

But stay tuned, will continue to provide pics of the stringer, transom, and floor replacement.

My new pool ...

 

[newbie_owner]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Thanks Andy,

However, I wanted to know, since he is not doing the stringerless deck, how much foam, if any, he is going to use with the traditional stringer job.

Wow, that was a lot of commas...

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

I think for now I'm going to leave the foam out. I don't believe that it served any structural purpose in this particular boat (there are some where it does). As I mentioned, I was going to go ahead with a lean towards foaming later so I'll wait until I'm ready to foam. Once foamed everything underneath the deck should be watertight. I want to be sure for now that the hull stays dry. If I put foam back in the areas that had them before, there is potential for water retention.

If I were to replace the foam that was there, I'd go with the 2lb. foam and I can't imagine that it would take any more than a 4lb. kit from US Composites at a little over 20 bucks.

 

[newbie_owner]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Thanks Driven1,

So you will be saving about $175 to $200 by doing the stringer job?

The progress looks great, this will really help me this winter.

Have you thought about paint at all?

 

[Andy in NY]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Thanks Andy,

However, I wanted to know, since he is not doing the stringerless deck, how much foam, if any, he is going to use with the traditional stringer job.

Wow, that was a lot of commas...

Right, I had forgotten about that.

I think for now I'm going to leave the foam out. I don't believe that it served any structural purpose in this particular boat (there are some where it does). As I mentioned, I was going to go ahead with a lean towards foaming later so I'll wait until I'm ready to foam. Once foamed everything underneath the deck should be watertight. I want to be sure for now that the hull stays dry. If I put foam back in the areas that had them before, there is potential for water retention.

If I were to replace the foam that was there, I'd go with the 2lb. foam and I can't imagine that it would take any more than a 4lb. kit from US Composites at a little over 20 bucks.

So, do you think it would really take alot less foam WITH stringers as opposed to all foam? Before you were talking about 15 cu ft (you said it worked out to be about 1 cu ft per foot of the boat for mgf's). Now you are talking a total of 2 cu ft? is that only because its not structral and there would be nearly as much foam?

I am really leaning towards the stringerless design myself. I am okay with spending a few extra hundred bucks.

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Yeah, that's pretty much it. The foam that was originally there was simply for floatation if the boat were swamped or capcised. It also comprised a small area in the bottom of the hull and was not filled to floor level. So no where near as much foam is required to fill the original areas.

In doing a stringerless foaming, the reasons for the foam are different. You're replacing the entire below deck structure with foam. The foam transfers energy from the transom to the hull, strenghtens the entire hull, provides extreme flotation, and provides support for the deck. This is why it's recommended to use 4lb foam because it has more structural strength. When it was done, you could shoot holes in the side of the boat and other than the holes, you'd never know it.

That's why in FreeGypsy's case, his boat is a much better candidate to use foam. He has 4 stringers, 3 or 4 bulkheads that run the width of the boat, and the floor. All of it totally rotted. It would save him an immense amount of time, and work to go the foaming route.

In my case, it's marginal. I've only got 2 stringers, 3 very small bulkheads, and the floor to deal with. I'd actually be doing more work to foam it. I do like the idea of the foam for my boat though due to the strenghtening of an old hull, mostly eliminating the possibility of future rot, and the additional safety factor. Really, other than the foam, I'm putting it back the way it was when it was new only better. ALL of the wood will be encapsulated in fiberglass and/or resin. MFG didn't do any of that, that's why they rot so bad. MFG didn't really have a system to get rid of water that got in the hull either. Another reason they rot so bad.

 

[Andy in NY]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Well, I guess I have a descision to make here. Replace the stringers and save money or all foam for a little bit more. Stringers scare me. How do you plan to get them the right shape?

Maybe if Newbie Owner does his stringers, I'll go check out the process on how he does it and make the choice weather or not thats what I want to do.



What kind of wood do you plan to use for the deck? PT ply or exterior grade ply?



ETA: Thought you might like this:
http://cgi.ebay.com/MFG-15-Gypsy-Bo..._trksidZp1638Q2em118Q2el1247#ebayphotohosting

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Andy,

As I recall, your boat is a 14 footer. I would expect (although not sure) that the stringers and bulkheads in your boat are pretty much the same as mine. Just 2 stringers and 2 or 3 bulkheads (crosspieces between the stringers). It would probably be cheaper and less work to just replace the stringers and floor and be done with it.

I think of it this way. The boat lasted probably 20 years or so manufactured the way it was. Because I'm going to be doing a better job than the manufacturer, I think that my work would easily last double that provided the boat is taken care of properly.

There was nothing special about the stringers in my boat. They weren't angled on the bottom to fit the angle of the hull. They were simply 4" strips of 3/4" plywood with square edges. The only area where there was any shaping done was near the console area where the bow starts to curve upward. The bottom of the stringers there were cut to follow that upward curve (but still had a square edge) to keep that portion of the deck level with the rest of it. That is the only area I have to worry about shaping the stringers.

I've come up with a way (I think) to trace that contour and then transfer it to the new stringers. I'll provide pics (if it works) when I do it. If it doesn't work, I have some other ideas.

The bulkheads would be a similar process. I was lucky in that one of my bulkheads came out mostly intact and I can use that as a template for the shape of the bottom of the new ones.

So, there's really nothing "scary" to replacing the stringers. It's a pretty straight-forward job.

I plan to use plain old exterior grade plywood for all of it. I'll be coating every last piece (including the new floor) with resin on all sides and totally glassing in the stringers and bulkheads to seal them from any possibility of water penetration in the future. I'm also going to build some good drainage into it. I've also decided to foam 2 areas under the floor along the outer edges of the deck that inherently hold water with "Great Stuff" just to keep water from pooling there.

In your case (I suspect) and mine, it would be more cost efficient, take less time, and be just as good a fix than doing the total foaming. In FreeGypsy's case, it's the opposite. Foaming would save him an immense amount of time and work.

 

[FreeGypsy]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

i think i asked this already but i dont remember so bare with me. do i need to make a way for the water that may (but should never) get under the deck to get out? how would one do that being as the foam would fill any chanels you try to leave

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

You could build some drainage into it but it shouldn't be necessary. The foam should fill every little nook and cranny below deck and totally seal the hull and underside of the deck from moisture. The foam product we've been talking about is extremely resistant to water and should last many, many, many, years. Just as long as the deck and Bilge well remain watertight, it should be a non-issue.

It does still bug me a little though so I was looking at ways to build something in. The biggest problem is that if you're designing something to allow water out, you're also designing something to allow water in. It may be better to just leave it alone and just be sure everything is sealed and remains that way.

 

[FreeGypsy]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

thats what i was thinking, i mean the whole point is to completely seal the underside of the deck from water. consider yourself lucky that your boat was already cleaned out when you started! I should have about 40 hours into the boat by time I get the old deck/stringers/transom/foam out! Quite the task to pull all that rotter waterlogged material out!

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

I wasn't all that lucky. I still had a lot of junk to rip out of the thing, not near as much as you though Plus, I've got way more grinding to do because of going ahead with stringers. I have to get a good base for all of the new fiberglass going in. Also have grinding to do to prep the parts that I had to cut that will be re-assembled later. Grinding fiberglass just ain't much fun. Damn messy!

If you go with the foam, you'll only have to prep-grind around the perimeter of the floor to glass the edges to the hull. The rest of it doesn't matter.

 

[dancudayo]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

I'm also doing a 15 ft gypsy, working on stringers and have same question about foam in between weaving, I don't think anyone answered this question. I have been grinding but I am afraid of taking off to much old fiberglass. I tried a wire brush, a wire wheel and even acetone as well as other solvents, but nothing seems to clean it out enough. Will the resin adhere to this stuff or dissolve it or something? Or is the only option more elbow grease with the grinder. I bought a belt sander so I could get a more even surface. Using the grinder leaves highs and lows that might provide air pockets when fiberglassing. Sorry if this was answered but I double checked and didn't see anything. Thanks ya'll Dan. By the way for the angle of the stringer to hull I used a compass and just ruff guessed, I plan to bed them in in thickend resin hoping to get a surer fit.

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

Yeah, I tried the same things to dissolve the foam residue with no luck. Nothing touched it. I didn't get any suggestions from anyone either. So...

I've ground down just enough to expose some of the old woven and in some spots all the way down to the hull due to large bubbles in the original woven that they attached the stringers with. Some of them were holding water!

I figure that even with the little bits of residue that are left, I should have more than sufficient surface area to hold the new stuff.

You'll be putting down mat 1st and rolling it in I would expect. Mat is very forgiving in slightly uneven surfaces just as long as you saturate and roll it well so you don't have to have a perfectly smooth surface. Close is good enough.

I plan on bedding the new stringers in with PL Adhesive or an equivilent.

Here's what I did to copy the hull contour for the new stringers. Just finished doing it in fact. Worked great.

First, using a straightedge, I determined where the contour started from the straight part of the hull. Then I just taped the cardboard to the outside of the stringer channel making it longer than the contour so I can match it up with the straight part of the stringers later. Then I ran my little "tracer" down through the channel copying the countour to the cardboard. I'll make a template out of the cardboard and trace the contour to the new stringers. Cut 'em and done!

 

[Ezrider_92356]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

i ground the old stringer glass all the way down to the hull but left 2 tabs front and back about an inch wide to hold them in place while bedding the stringers the next day after the PL was cured i ground off my tabs and glassed the stringers onto the hull

 

[FreeGypsy]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

ok next few ?'s say ive got my boat all cleaned out and im ready to put int he floor do i have to coat the wood entirely in epoxy resin, or just the edges where it meets the hull? also how do you refinish the hull mine has pitting along the water line? Does anyone know where i can get a good price on a controller? looking for used as things all appear to be much much more expensive than i thought.

 

[Driven1]

Re: MFG Gypsy 15 Tri-Hull Restore advice needed

BIG NOTE: I noticed on my boat that once the entire floor was out, the hull had a twist to it from front to back. You'll want to check for that and correct it before putting the floor in. You can see it by looking from the back of the boat to the front using the transom and front bow edges as guides. If you glass the floor in with a twist in the hull, you will lock that twist into the hull and the boat will not perform well when in the water.

I think it's your call on the resin. You'll be applying resin to the top edges of the floor when you glass the floor to the hull. As far as the floor top coat itself, you could glass the whole thing with a couple layers of mat or go with another product like epoxy paints or Tuff-Coat. Foam should seal everything underneath the floor but to be on the safe side you could seal it with resin. Because I'm not using foam I will be coating everything.

As far as the pitting on the outside of the hull, there's lots of options. I depends on what you want in the way of a finish. You can use Gelcoats, enamel, or epoxy paints. Refinishing itself is pretty much the same as preping for and doing an automotive paint job. Search for painting in the thread. Tons of info!

You'll just have to keep an eye out for a controller on e-bay, craig's list, etc. Check around local boat repair shops for used ones. Making sure of course that it will work with your particular motor.