what wood to use???? do i really need marine grade???? - Page 3

Sean H · 04-01-2009, 06:04 PM

Quote:

Originally Posted by pasquesi

You could use Microlam material. It's a structural dimensional material made by pressing thousands of strands of lumber together bonded with exterior glue. It comes in 1 7/8" thickness, and widths from 9 1/2" up to and beyond 24". Since you will be encapsulationg it in resin anyway, that would be the stongest product I know of in that dimension.

actually, a microlam is an LVL product (laminated veneer lumber), the product with all the strands would be a parallam, a microlam is vastly stronger than a paralam. many boats have used LVL for stringers and other things before.

regalman4925 · 04-01-2009, 06:23 PM

Quote:

Originally Posted by northernoffshore

marine grade ply has more laminates inn it . count the side of it, the layers 1/2 shold be 7,3/4 about 9 layers

yea we figured that out but i dont think tha it makes it any stronger though? i think i am going to use a good quality exterior grade plywood. now i need to figure out if i can get by with polyester resin or if i need to go fo epoxy??

pasquesi · 04-01-2009, 06:46 PM

Quote:

Originally Posted by Sean H

actually, a microlam is an LVL product (laminated veneer lumber), the product with all the strands would be a parallam, a microlam is vastly stronger than a paralam. many boats have used LVL for stringers and other things before.

I stand corrected!

glassdave · 04-01-2009, 06:52 PM

poly is fine or even vinylester for your project, again its a cost thing. Sure epoxy is going to be better/stronger but is it a benefit you will utilize? You will have longer working times with epoxy and wet out is a different process than poly and can even make the process easier if staged properly. My biggest gripe with using epoxy in the bilge of your average boat is finishing it off. With poly its as simple as dump gunning gel on and tipping the finish. Epoxied fiberglass takes a bit more elbow grease to get a good finish. Margin call but for me i prefer poly or vinyl unless its something i am really looking for ultimate strength.

Sean you have any info on Microlam? whos using it in boats? Sounds interesting.

bigboat28 · 04-01-2009, 07:31 PM

Glassdave what would be the price on replacing a bulkhead in a 28' Apache? The engine compartment bulkhead.

regalman4925 · 04-02-2009, 12:15 PM

glass dave you are a huge help! thanks! now tell me this, is the polyester resin i can buy at wal mart or the parts going to be good enough? is there a brand that is better or worse or are they all about the same? the more i can get in town the better since i can go get more if i run out and i already got a bunch of resin from past projects not related to boats, i would like to use it up before it is no good.

next question is when i bond all of these sheets to the back of the bhoat do i just coat it with resin and stick it on or should i use mat in there? if so do i apply the mat to the wood or the back of the boat? also on my buddies 25 outlaw we are doing and i have not gotten deep enough on mine to know but there is a layer of filler between the wood and the fiberglass on the boat? should we leave that as is and glue to that or remove it to the glass? should we use resin or resin and mat between layers? sorry to ask all the questions but this is my first transom. i have done other fiberglass projects in the past so i am pretty confident that i can do this lol.

regalman4925 · 04-02-2009, 01:35 PM

heres another question, i have been calling around on wood, is the normal pine plywood in a exterior grade going to be what ia m looking for when we are talking exterior grade wood? i asked about others but i was told that it was pretty much standard? i just want to be sure before i get it all done and find out i used the wrong stuff. i am planning to finish tearing out the transom this weekend if the weather holds up and cut the new pieces out and fit them, hopefully next weekend i can install and start the stringers. thanks all for the help!

regalman4925 · 04-02-2009, 03:32 PM

i can get other wood besides pine and still be less then the half of the cost of marine grade. marine grade at this point is out of the question for me. is birch good, its 40 a sheet?

fantastixvoyage · 04-02-2009, 04:23 PM

This has been an interesting read. I've always been told not to use marine grade. This it due to it NOT taking resin well, much like oily pine that has been mentioned. Basically the additive used to make marine grade is an oil (reacts different with resin) thus making raw wood a better selection. Thoughts?

Some pieces in my last boat were marine grade, no resin. Totally rotted. To me off-the-shelf marine grade is porch/deck grade. Any wood going into a boat should receive resin as a seal. correct?

No one is saying to use the wood as purchased, so comparison of them as stand alone tells me nothing. Compatibilty to resin is what I would like to know.

regalman4925 · 04-02-2009, 04:47 PM

i was told by the pro in town that it is a waste of money to use marine grade, thing i forgot to ask was what type of plywood to get, pine is apparantly a bad choice...

i dont think my home depot stocks marine grade plywood, i am in the middle of the midwest so there is a small demand for it, its all 80-100 a sheet and special order from ehat i can find.