DIY swim platform??

[fourwinnsdook]

I have an 86 four winns fish and ski, and i'de like to build a large swim platform for it. has anyone done this? I've searched and didn't find much. I'm basically needing the methods of building the platform itself woods/plastics to use. how to fasten/glue it together.Where to buy materials. Any help would be appreciated.I'm not to worried about the designe, more so of the fasteners/glue to use, and what wood/how to treat it.

Thanks!

 

[OhWellcraft]

Re: DIY swim platform??

Fourwinnsdook,
I built one about five years ago on a 18' ski boat I had at the time. I used aluminum angle 1/8" and 1"x1" aluminum tube. Angle for ledgers on transom and supports under platform and tube for knee braces to support water edge of deck. I ended up using 3/4" redwood that was oiled up very well on all sides etc. I thought about using trex or a similar composite wood product but it is somewhat heavy and doesn't take a screw too well. I glued up the deck real well with a good waterproof wood glue and clamped with bar clamps overnight. Then used the angle on the underneath side to help hold togather and to give a means to attach knee braces. I used gorilla glue then sanded and finished after all was dry. It really helped me to look at one at a marina to get an idea on how to attach everything and how to best assemble it all. I wish I had a foto of it to show you or some means to draw it up. Teak is another option but it sure is expensive to buy. I have also heard of people using all thread to hold them togather but seemed like a lot of extra work to me. I did a grated type not a solid one might have some cupping issues if went with a solid one. I know this is probably hard to understand but it can be done MUCH cheaper than buying one. Mine lasted great right up until I sold the boat (4 years later) I did however oil it up a few times to help keep the wood. Good luck maybe someone else will chime in also there a lot of very knowledgeable folks here.

 

[pjrogers]

Re: DIY swim platform??

A plastics shop can sell you a marine-grade sheet called King Starboard, see:
http://www.kingstarboard.com. I've used this stuff to rebuild boat seat frames, and it is pretty good. Holds a screw pretty well. You can glue it too, with a special two part adhesive they will sell to you. The 1 inch thick material would probably be strong enough for a swim platform. Never having built a swimgrid, I can't say how to put it together, but I suspect that your support brackets could be secured to the platform with stainless steel bolts. I would counter-bore and plug the bolt heads on the upper side of the platform, and use bolts with nylon thread lock or some other locking compound on the nuts. You might want to glue an extra thickness of Starboard under the point where the support beams attach to the grid. The support beam's bolt holes in the transom should be filled with 3M 5200 or similar, and obviously you would want big washers on all sides of the support bolts to spread the load. No doubt you could find stainless steel 90 degree angle somewhere for the ledge support between your transom and the platform. You would want to use many bolts to secure that connection. Fabricating the stainless support members that go out to the stern edge of the platform would be the trickiest bit. Probably require some assistance from a welding or machine shop, and some, say 1/2" plywood, templates made by you for shop's use as a pattern. Two beefy support beams one to port and one to starboard would likely be sufficient. As for decorative trim, teak's the obvious choice, but Ipe is readily available and nearly as resistant to rot. I don't thing you could glue the wood to the plastic, so many stainless wood screws through the wood into the edge of the grid would be necessary. Again, counter bored and plugged holes would be the method. If you use teak, don't forget to wash the plugs and the holes they go into with acetone before gluing the plugs in place - teak exudes oil which, if not washed off the wood's surface, will prevent the glue from giving you a good joint. Also, have a look at this month's Fine Woodworking magazine - an article there about glues will probably steer you away from using Gorilla Glue or its ilk for this project.

 

[fourwinnsdook]

Re: DIY swim platform??

Thanks for the good ideas, keep em comming. i was thinking of using a red wood.

 

[OhWellcraft]

Re: DIY swim platform??

I agree with pjrogers on all points, however trying to work with stainless as a do it yourselfer can be very difficult. It takes very specialized drill bits, saw blades, etc. plus is quite expensive. It's a toss up between the two, I have seen as many done with aluminum as I have with stainless. They do make a bracket for the square tube to fit in that helps a lot with the angle of the knee braces and the transom.
l
l================ DECK
l ` ``````````` * \
l * alum angle
l *
l * knee brace
l * ( tube )
l *
l ___ *
l __*/ bracket
_____l

 

[OhWellcraft]

Re: DIY swim platform??

Well my neat drawing didn't turn out right so omit the bottom half of last post sorry about that...

 

[seafrog]

Re: DIY swim platform??

I built one this past week and tried it out for the first time yesterday at the lake. Performed beautifully. I took some photos, and will upload them soon. In the meantime, here's what I did:

To save a bit of money, I was going to build with Douglas Fir. However, Mahogany was cheaper - something about the market being flooded with Exotic woods right now. I forget the whole story from the lumber guy, but suffice to say, I went with the mahogany (S4S). I bought enough 1x6's and 1x4's to construct a 6'x22" platform, as well as #8 SS screws and Marine Goop to glue and screw. The screws were fastened from underneath the platform for aesthetics. Total cost? 100 bucks. The platform was built with 1/4" spacing to allow drainage as well as dissipating the "slap" of waves and ripples hitting from underneath. When finished, I sanded with 120 grit and then down to a final of 220. After considerable research, I settled on using Penofin Marine Finish. This is really a great product - goes on easy and requires only one coat. Not cheap (about 35 buck/quart), but I have enough leftover to do another 4 platforms!

For hardware, I had a hell of a time deciding what to do. In case you haven't noticed, supports are very expensive - about $85 apiece. They must be 24 kt gold filled. Anyway, I went to a local welder/metal fabricator and had them cut 4 lengths of SS 7/8 tubing which they flattened with a press at both ends. I then bent these in my vice to the required angles to match the transom and platform as well as drill two holes at each flattened end. I also had them cut me three pieces of aluminum L bracket to mount the leading edge of the platform onto the transom. The poles then project outward to the trailing edges of the platform. Total cost for the hardware - 70 dollars! The result is a structure that easily supports the weight of both my son and I. VERY strong indeed. All screws into the transom were sealed with 3M 5200. Screws were #12 for mounting the hardware.

Heed: Be prepared to toast a few drill bits on the tubes. If you decide to spend a few extra dollars on cobalt bits, it'll make the job easier. Slow and steady is the trick. It can be done with reg or titanium bits, but you'll burn a few up!

I've decided that it came out so nice that I'll likely begin making and selling them on EBay. It looks very similar to platforms you see on Tiges, Mastercrafts, etc.

 

[OMCboater]

Re: DIY swim platform??

Seafrog, I would sure love to see some pics of it!

 

[idaho_rmk]

Re: DIY swim platform??

I have been trying to figure out all of these same things.
I was thinking of doing it with TREX and coming up with something like the Plasteak product. I found this link that shows an install which shows everything you really need to know except how each of the trex type material is held together. I was thinking something like a ready rod through the whole thing.
Here is the link.
http://schumacher.sdsmt.edu/other/Boat/Swim Platform Install/plasteak_swim_platform_install.htm

I'm also interested to see your pictures seafrog.

 

[wire2]

Re: DIY swim platform??

Some hints about working with stainless;

SLOW cutting speeds rule, drills and saws.

Drill bits must be good quality.
Keep enough pressure on the drill to make it "dig" a bit. Cutting fluid is beneficial.
If it spins in the hole without cutting, the stainless heats, discolors and goes very hard.
Then it's really tough to complete the hole.
If it does heat & smoke, check the drill tip corners. They're the 1st to go. Sharpen on a fine stone.


A friend has a weld/fab shop, equipment includes a large band saw. Carbon steel cuts well at 400 fpm, stainless will destroy a $65 blade in 10 seconds at any more than 100 fpm.

 

[seafrog]

Re: DIY swim platform??

I tried posting pics of my project here, but this site only allows very small file sizes and I'm not sure how to reduce my pics to fit. I tried properties, etc. Anyway, I did post lots of pics on shareaproject.com and you can go there to see them. Look for "Campion Allante" and "swim platform" in the "boats" section and you'll see them there. I'm interested to get honest reactions. As I said in a previous post, I may make and sell these in my spare time. But as my wife says...."WHAT spare time???" LOL

Like Wire2 said, "slow and steady" when drilling or cutting SS. Interestingly though, I found the cheap bits cut the best for me! (???) Not sure why, but they did. Just don't allow the bit to get too hot.

 

[sdunt]

Re: DIY swim platform??

I did post lots of pics on shareaproject.com and you can go there to see them. Look for "Campion Allante" and "swim platform" in the "boats" section and you'll see them there.

It looks like the project is at; http://www.shareaproject.com/pages/projectTut,p,393,00.html

 

[seafrog]

Re: DIY swim platform??

Whoa!! Thanx Sdunt! When I tried to cut and paste a link to the page, it only took you to the main page (home page) of shareaproject.com (?) It wanted to bypass the exact page you provided. Thanks again!

I should add: The support poles in the picture do not show the extra work I did on them. After these pics were taken, I wet-sanded them to give them the shine of polished SS. The pics show them in their "raw" state. This added an hour to the job but was really worthwhile.

 

[1970 Chieftain V]

Re: DIY swim platform??

Very nice deck seafrog. I hope to do one of those soon.

Jason

 

[jedimaster]

Re: DIY swim platform??

Depending on how much your looking to spend you may want to plook at one of these things.http://cgi.ebay.ca/AFI-84-White-Pol...ryZ50443QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[seafrog]

Re: DIY swim platform??

Thanx Chieftain! Jedi: Yeah, I almost went with one of those, but found it too narrow (17 inches). Probably due to syn woods hefty weight compared to wood? Plus, I'm a cheap bastard and also wanted to play with my woodworking tools! LOL!!

Question: My leg contacts the platform ever so slightly on full trailer up position. Is there a way too adjust the maximum "up" position? We're talking a Mercruiser Alpha leg on a 5.7L

 

[clancy72]

Re: DIY swim platform??

This place does a great job for a fair price.http://thecuttingboardfactory.com/M...Screen=CTGY&Store_Code=TCBF&Category_Code=4MB Follow this link for pics and discussions, http://www.hotboat.com/forums/showthread.php?t=118579
They come in colors, and non-slip finishes.

 

[petergordon]

Re: DIY swim platform??

I know that this thread is a bit dated, but it (and some other) threads really helped me when building my own swim platform.
I had the brackets made for me at 105 degrees (transom slope). Some 1/8 SS plate and some 3/4" SS pipe. I made the platform out of cedar 5/4" deck boards, ripped them to 4.5" wide so that I could fit the right width. 4 brackets across the transom, used 3M 4200 (bought at Canadian Tire store in Brockville) to seal the holes. A friend of mine at work did a stress calculation on 1/4" bolts, and we opted to go with 3/8 because of the results.
Note, no matter how smart you are and how far ahead you plan, you need to measure where you are drilling through your transom into the INSIDE. I just about drilled into my gas fill line and into my trim hoses. Also, I got lucky when I drilled the holes in the brackets first and then matched them to the hull, because I would have been SOL in I had drilled my lower hull hole another 1/2" lower, I'd have been into a stringer and would not have been able to nut the bolt.
The wood was about $70. Box of cedar screws, 3m 4200, tung oil, etc. But the ladder... I fould one locally for $255 tax in (canadian) when I could have bought it for $135 USD. I paid the extra $100 willingly due to time and, well, just wanting to get the thing done and not have to worry about shipping delays. So the ladder is about 70% of the cost of the platform.
I love it! It mounted a bit higher than the stock ladder, but I went with a windline 3 step ladder with hand bar.

 

[dustedwatts]

Re: DIY swim platform??

I built one this past week and tried it out for the first time yesterday at the lake. Performed beautifully. I took some photos, and will upload them soon. In the meantime, here's what I did:

To save a bit of money, I was going to build with Douglas Fir. However, Mahogany was cheaper - something about the market being flooded with Exotic woods right now. I forget the whole story from the lumber guy, but suffice to say, I went with the mahogany (S4S). I bought enough 1x6's and 1x4's to construct a 6'x22" platform, as well as #8 SS screws and Marine Goop to glue and screw. The screws were fastened from underneath the platform for aesthetics. Total cost? 100 bucks. The platform was built with 1/4" spacing to allow drainage as well as dissipating the "slap" of waves and ripples hitting from underneath. When finished, I sanded with 120 grit and then down to a final of 220. After considerable research, I settled on using Penofin Marine Finish. This is really a great product - goes on easy and requires only one coat. Not cheap (about 35 buck/quart), but I have enough leftover to do another 4 platforms!

For hardware, I had a hell of a time deciding what to do. In case you haven't noticed, supports are very expensive - about $85 apiece. They must be 24 kt gold filled. Anyway, I went to a local welder/metal fabricator and had them cut 4 lengths of SS 7/8 tubing which they flattened with a press at both ends. I then bent these in my vice to the required angles to match the transom and platform as well as drill two holes at each flattened end. I also had them cut me three pieces of aluminum L bracket to mount the leading edge of the platform onto the transom. The poles then project outward to the trailing edges of the platform. Total cost for the hardware - 70 dollars! The result is a structure that easily supports the weight of both my son and I. VERY strong indeed. All screws into the transom were sealed with 3M 5200. Screws were #12 for mounting the hardware.

Heed: Be prepared to toast a few drill bits on the tubes. If you decide to spend a few extra dollars on cobalt bits, it'll make the job easier. Slow and steady is the trick. It can be done with reg or titanium bits, but you'll burn a few up!

I've decided that it came out so nice that I'll likely begin making and selling them on EBay. It looks very similar to platforms you see on Tiges, Mastercrafts, etc.

I really like your platform... i just have one question.

your L brackets, why did you place them were you did, why not on the same places you mounted the ss tubing?

 

[boat freak]

Re: DIY swim platform??

I was just talking about this with a buddy of mine. Since baja made a stainless steel painted one for it's outlaw series boats. Why can't one simply use chain link fence line poles for the pieces. I think those are about 1 to 1 1/2 inch's around. Use the parts that go with chainlink as your corners and support points. Then just powder coat the whole thing. You can buy powder coat at harbor freight in various color cheaply. I don't mean to sound cheap I just wondered why that wouldn't work. Actually you rent a conduit bender for your local rental store and actually bend the corners if you wanted. I certainly would hold weight and you could do the whole thing for less than a hundred bucks painted etc.... You could get real detailed and weld the whole thing together. Actually they sell cheap welders for less than $200. I only mention that because for the price of what they want for the ones already made you could build one yourself out of stainless including buying a welder paint gun and air compressor. Last I saw they were $1500. I understand profit but that's just silly.