New Member Question

Hi, I have been looking at this forum for years and I have finally registered.

(there's a reason for everyting)

I have recently purchased the last ORIGINAL 37 Midnight Express. The boat was just completed and laid up with vinylester resin and mantex 1" foam coring was used throughout. The tranom is nearly 4" thick and has knees tied into stringers for transom strength.

It also has 3 center line fuel tanks tha are running from stern to cabin. And then from mid cabin to bow. They are glassed and foamed in between stringers and bulkeads.

The boat was specifically made for quad outboards, will have a top speed of 85-90 + and will be used for pleasure.

The builder has the molds but no longer produces the boat. He builds 40 and 60 ft sportfishers now.

The boat is home now and I am finishing the cuddy area with bench tops, top for berth, 2 forward bulkeads for top deck support and several other bulk heads in bow of boat under anchor locker.


So now to the dilemma.

Builder says use low density coring to finish cabin bulkheads, bench tops etc......, layer of 1.5 ounce cloth on both sides, tab in with two layers of 1708.

Other opinions have been........ 1708 on both sides, heavy denisty coring. Tab in w/2 layers of 1708

OR......low density w/1708 tab in w/ 1708 My Choice......

Cabin is going to then be gel coated and eventually covered in uphosltery so appearance is not the major concern. Important but not expected to be " faired" Obviously strength is my concern.




What should I do?????

Can I go with a lighter cloth say 10 oz cloth and tab in with 1708, can I use polyester resin instead of vinylester for this or........

I am trying to keep budget down and not waste or use materials that I don't need. But I aslo want confidence when offshore travelling st high speeds and going through the inlet.

Also not a lot of info on Mantex coring but seems to be in line with others.
12-15 lb density, 18-22 lb and 24-28 lb

Any advice..............PLEASE

 

Anyone????

 

Quadm, sounds like the builder want you to chase weight out of the fitout with light bulkheads etc, at 1.5 oz cloth on the foam thats kind of on the border for needing chop to lay first onto the foam- sounds like he wants to leave it out & therefore save about 2lbs( each side) per square meter/yard(roughly), once overweight is built in its hard to chase out, also a good "guide" for tabbing is equal to the thinner laminate of the structure although sometimes the designer is looking for more to kinda get some 0 axis fiber "ringing" the bulkhead & might also want some extra in the bottom tabbing, I'd stick with what the builder recomends- if he's done a few with no probs thats a good thing, & stick with the vinylester but buy in quantitys you can use quick if your taking some time over the fitout, if the boat didnt sound "extreme" poly would do it but it sounds like hard running machine to me! All the best from Jeff.

 

Problem solved. Talked to builder again and questioned the technique. He misunderstood question and assumed I knew to put top and bottom layer of 1708 on first and then 1.5oz cloth for finish. Now I am