SIB Mods & Repairs

[theboysmiffy]

Hi all. Took the sib out on the North Sea for it's maiden voyage on Friday and it performed admirably considering it's age, cost and untried nature! Two up, it got onto the plane and fairly flew. The motor needs it's carbs cleaning and a tune up as it hasn't been in use for a while and is down on power. A few things became evident though that I want to address. There are air leaks in the tubes which could be holes or the valves, going to do the soapy water test at the weekend. There is quite a bit of flex in the structure of the boat, with the boards almost buckling up just before it gets onto the plane. The transom is at its capacity with the 35hp motor and could do with some strengthening, I'm going to design a steel tubular frame. If anyone can help with these that would be great (photos of trip to follow soon):

1. What is the best product for cleaning the hypalon?
2. How do you remove old patches and glue (heat gun and sandpaper 100)?
3. Who manufactures the best Glue and repair patches?
4. Has anyone made a subframe/brace that joins the transom and rear ply floor?
5. Has anyone installed wooden 'chassis rails' to connect all the ply floors together and add rigidty?

Apologies for all these questions! I know someone here will have the answers.

Thanks

[m chappelow]

the inflatable keel may not have had enough pressure in it which will cause the boards to buckle a bit ,dont forget that as soon as the boat hits the cold water you get a slight pressure drop so they usually need topping up once the boats been in the water a few mins, and your quest 4 some boats do have a brace between the transom and floor either triangular wooden gussets or metal rods,and with regards to boards having a brace in your question 5 most do have some form of longidudal strengthning rails ,

[1ThOFA87]

Originally Posted by m chappelow

the inflatable keel may not have had enough pressure in it which will cause the boards to buckle a bit ,dont forget that as soon as the boat hits the cold water you get a slight pressure drop so they usually need topping up once the boats been in the water a few mins, and your quest 4 some boats do have a brace between the transom and floor either triangular wooden gussets or metal rods,and with regards to boards having a brace in your question 5 most do have some form of longidudal strengthning rails ,

I think this is what was happening to me. I had igloo coolers as seating and when i got my speed up, the one I was sitting on at the back of the boat (attached to second floor board)seemed to pitch back as the one that my feed were on seemed to pitch forward forcing me to come off of the throttle a bit. If this is what you're referring to, thanks so much for the advice. It makes perfect sense!

[m chappelow]

i dont get buckling of floor boards nowadays as mine is a one piece floorboard but with other boats of mine in the past i have noticed more buckling when surfing down a large swell or wave more than getting on the plane .but if you have multi boards you do get a bit of flexing and groaning /creeking noises.,,,,dont forget ,, theboysmiffy,,,your boat was built to be diasembled as small as possible but then have the ability to carry a group of soldiers with there full kit .

[theboysmiffy]

Thanks for the advice. I re inflated the boat once on the water to allow for the cooling effect then again later as the tubes lost pressure due to air leaks. I was going to fabricate the transom bracket from tubular steel with attatchments for the fuel tank. The board bracing I was going to make out of soft wood probably 2" x 2", do you think this would be suitable? I'm determined to iron out all the little flaws!

[Rogue Wave]

Tube repairs

Lift old patches off with a bit of heat gun and a spatula type tool. Not to much heat once you have an edge to grip use fingers or pliers to help the process. Tease the patch off don't tear it.
.

I have some Avon grey mayerial BTW which I don't need

Doing the Gluing

what you need to do is very thoroughly prepare your surfaces, they have to be roughed up very well! You can do it with a plastic wire brush in a drill. I'm actually doing this at the moment so if you pm me your number I'll text you some pictures of the roughness.


tools needed
Bostik 2402 , bodtikure d10 hardener
Drill
Plastic wire brush http://www.tooled-up.com/MicroCatego...=3877#prodlist
Heat Gun
Paint brush
Thinners
Masking tape
Roller or heavy scraper.
disposable latex gloves

After prepping the strake tubes wipe down with a rag and thinners. after a while waft the heat gun over the areas to ensure evaporation of thinners.

Masking tape either side of the glue line will ensure no overspill of glue but you want 10 mm width more glue on the tubes than the patch, it comes off easily.

Mix the glue up with a small amount of thinners 10% and hardener, stir for 2 minutes. Paint a thin coat on both surfaces when this dry do it again. previous to this you will have put on 2 pairs of the disposable gloves. It means you can get rid of the top pair when it gets too gluey. When this coat becomes tacky you have to do the sticking

Now that you have gotten wasted on the glue fumes the job becomes a lot more fun. I guess I forget to mention Ventilated work area

When you apply the patch it's a one time hit so you need to get it right.. when it's in place work the heat gun over it and rub it in firmly with the roller.


If you get it wrong start at the top and do it again

cheers stu

PS You find you leaks with washing up liwuid solution or if your'e a diver Snoopy

Cleaning Depending on how grundgy the tubes are I'd use thinners or TFR rub it on wash it off quick

[oujakov]

Originally Posted by theboysmiffy

4. Has anyone made a subframe/brace that joins the transom and rear ply floor?
5. Has anyone installed wooden 'chassis rails' to connect all the ply floors together and add rigidty?

Apologies for all these questions! I know someone here will have the answers.

Thanks

Remember!

The properly installed floor boards designed to enchance the rigity of the whole boat and the especially at the transom. Upon inserting the last piece of floor board, you should have to use slight pressure for inserting it. It has to strech to the hull of the boat by a little bit, e.g. creating the pressure point at the bow point and the the transom lower bracket (near the drain plug area).
See, the weight of the outboard will push the lower part of the transom inside the boat, properly fixed floor will create back pressure to kepp the transom from falling of and keep the boat from flexing.

You must use the 'chassis rails' to set the floor boards, otherwise under load your floor boards may collaps upwards

This is how you can "increase" the rigity of the transom, nothing extra to do just has to be done the right way.

[theboysmiffy]

That make sense, the boards had buckled up and moved about 2" away from the transom by overlapping themselves. The rails I was considering installing would counter this by tying all of the boards together and preventing movement. I never really considered that the rear floor board would be counteracting the turning force of the transom. I thought a brace here might just strengthen up and prevent any more twisting by spreading the load. Do you know what the chassis rails are made of on other boats? ours didn't come with any.
Thanks. Adam

[theboysmiffy]

Thanks for the repair advice Rogue Wave. I will be starting the repairs this weekend. Do you leave the boat inflated?

[urbanbiketech]

I did see on the military spec zodiac (fc470??) that there are straps running from the inside top edge of the transom down to the floor about a foot forward of the transom. My assumption was that this was to provide extra bracing to the transom because of the the bigger engines used.

http://www.rib.net/forum/attachment....9&d=1234379864