Wharram Builders and Friends

A Photo & Discussion Forum for Wharram Design Enthusiasts

On the plans, lot of nails are used to hold pieces with epoxy. Epoxy and clamps or under pression with some weight is not good enough?

Views: 1320

Reply to This

Replies to This Discussion

Put the pieces together and hold them with clamps. Drill holes at some places. Unclamp, put your glue, and insert wooden dowels in the holes. When you assemble them again with the glue, your pieces will be at the exact place as when you clamped them at first, and will not slip when you fasten them either with screws or nails. Yo may of course leave the dowels inside, as long as they are coated or covered.

It was an 82' commercial charter power catamaran that carried 100 people at 33 knots using two 600hp John Deere diesels with two 20kW generators to keep all of the systems running. It is more than possible to use 2000lb of screws in such construction. Most people have little concept of weights and how they can affect a vessel. On another power cat that we installed the electrical and environmental systems, we saved 3000lbs in wire weight by going with 240VAC and 24VDC systems. I am not talking about Wharrams here. However, the rules still apply: 40 extra pounds here, 100 there, 30 here, 10 there, and it all starts to add up.



wakataitea said:



Budget Boater said:

Long ago, I assisted in building a high tech commercial power cat. Once it was completed, the owner/designer was confused by the lack of speed (which was extremely important for this vessel) of nearly two knots at cruising RPM.

We spent a few days going over everything, including the plans, discussions with the company that did the final assembly, and so on. Then suddenly, during a brainstorming session on the lack of speed, the owner burst out, "it's the screws!"

It seems he had neglected to include the nearly 2000lbs of screws used to assemble the boat in the total weight calculations. It cost him nearly $25,000 to rectify the error with new props to account for the extra weight.


i do not believe this. 2000LBs this are 900kg... was the boat the sice of the titanic???

i use on my tiki46 maybe 15 kg of 306 SScrews and i screwed every thing togeather. we are talking abiut building a wharram and not a racing cat. i used Gaboon ply insteed of mahogani. this saves you 500kg on weight for a tiki46. if you look at, what the people put on stuff on board once they go cruising, then we knw that this screws can not be an issue.

It is possible to remove the screws and then used a syringe to back fill the holes completely. The idea is to not over thicken the epoxy so that is can squeeze through the needle. We use this technique regularly. We also simply press thickened epoxy into the holes, and don't sweat the small bubble. What is the worst that can happen? The bubble exists in an area that is completely surrounded by epoxy, and the joint itself is solid. We have never had a failure due to a 3mm void where a fastener once lived.

You can also use the matchstick method....



agur said:

PS! Im still wondering is it possible that after I had removed the screws and filleted their holes - there will be still enough air trapped to cause trouble in the future....?

Does someone had experience with this kind of issue...?

Get several boxes of wooden matches. Mix some epoxy and dip the stick in the epoxy and push them into the holes. Cut off the heads with a knife. Sand after cure. The hole is now filled with wood and epoxy.

(Realistically, you will likely need to smear a tiny bit of thickened epoxy over the holes after sanding due to small hollows that develop during the process.)

agur said:

Thanks for the reply.

Yes its easy to get carried away with those detailed nuances...

Hmm, what is matchstick method?

Budget Boater said:

It is possible to remove the screws and then used a syringe to back fill the holes completely. The idea is to not over thicken the epoxy so that is can squeeze through the needle. We use this technique regularly. We also simply press thickened epoxy into the holes, and don't sweat the small bubble. What is the worst that can happen? The bubble exists in an area that is completely surrounded by epoxy, and the joint itself is solid. We have never had a failure due to a 3mm void where a fastener once lived.

You can also use the matchstick method....



agur said:

PS! Im still wondering is it possible that after I had removed the screws and filleted their holes - there will be still enough air trapped to cause trouble in the future....?

Does someone had experience with this kind of issue...?

matchstick method... sound very profesional.....

 that's the reason why wharram catamarans a considered as a cheap home build fuck up.... jesus.

when do you guys start working profesional.

imagine you get a boat build in a shipyard and this guys fill the holes with matchsticks... would you exept this???? sure not.

but you do this kind of shit on your own boat... i can not believe this... talking about using the best ply wood, B1088 and all then you are filling the screw holes with the cheapes wood in the world... great job, guys...

i can only shake my head... this sounds realy like BUDGET boater..

 sorry mate, but you disapoint me. i thought you produce profesional quality build boats..

Quote:- Does someone had an experience with this kind of issue.

Yes----Lots.

Ring nailing, screwing and bolting all have their time and place, but when time = money the fastest effective method is the best. 

I was faced with disbelief when I said we built a wooden Tehini in four weeks. 

For major high stressed parts we used thru bolting. Crossbeams, deck fittings and sail sheet tracks for instance. 

But for regular work, like sheathing the hulls with ply, we used bronze staples with epoxy coated legs. 

The instant heat of pneumatically driving the staples softened the epoxy so it bonded instantly to the wood, making it almost impossible to remove. Gas powered staple guns are readily available to rent these days.

 

Well, that's a bit harsh, don't you think?

The fact is, the "inferior" wood the matchstick is cut from, will soak up more epoxy, in essence becoming resin infused, and be a better choice than a harder, marine "certified' timber. And, no, I haven't done it. My preference is to just fill the hole with thickened epoxy and move on. I don't see anything wrong with the matchstick method other than it's a bit labor intensive for my taste.

Omar
 
wakataitea said:

matchstick method... sound very profesional.....

 that's the reason why wharram catamarans a considered as a cheap home build fuck up.... jesus.

when do you guys start working profesional.

imagine you get a boat build in a shipyard and this guys fill the holes with matchsticks... would you exept this???? sure not.

but you do this kind of shit on your own boat... i can not believe this... talking about using the best ply wood, B1088 and all then you are filling the screw holes with the cheapes wood in the world... great job, guys...

i can only shake my head... this sounds realy like BUDGET boater..

 sorry mate, but you disapoint me. i thought you produce profesional quality build boats..

Way up on that High Horse, I see.

The matchstick method is listed as THE technique in the Wharram plans, which is why I mentioned it, not because I use it, not that it matters anyway; because if you actually build a Wharram "to plans", then it will have matchsticks in it. Considering that no one I know uses this method, then we should assume that there are only a few Wharrams built "to plans", all of which were built/overseen by Wharram/Boon.

So I guess you would not be caught dead or alive on Spirit of Gaia since it probably has matchsticks filling the voids.

Wharram, the original BUDGET boater. I will wear that badge proudly....

If that disappoints you, I am sure I will get over it.



wakataitea said:

matchstick method... sound very profesional.....

 that's the reason why wharram catamarans a considered as a cheap home build fuck up.... jesus.

when do you guys start working profesional.

imagine you get a boat build in a shipyard and this guys fill the holes with matchsticks... would you exept this???? sure not.

but you do this kind of shit on your own boat... i can not believe this... talking about using the best ply wood, B1088 and all then you are filling the screw holes with the cheapes wood in the world... great job, guys...

i can only shake my head... this sounds realy like BUDGET boater..

 sorry mate, but you disapoint me. i thought you produce profesional quality build boats..

I agree Hans...be simple, use mass, wood powder + silica. Don't worry.

Reply to Discussion

RSS

© 2017   Created by Budget Boater.   Powered by

Badges  |  Report an Issue  |  Terms of Service