View Full Version : What does GRP mean?

Steve Lansdowne
11-23-2002, 06:03 PM
Reading a Water Craft magazine, I've come across the term GRP, as opposed to wood. What specifically does it mean, or stand for. I presume it is the same material as we refer to nonaffectionately on the Forum as #&*$#@!!!

Bill Perkins
11-23-2002, 06:09 PM
Glass Reinforced Plastic I think .

capt jake
11-23-2002, 06:12 PM
Yup, that's it!! Just trying to think of that when you posted. Good goin'! smile.gif

11-23-2002, 06:22 PM
I rather thought it was Glass Reinforced Polyester, but I might well be wrong.

I'll stick with what LFH called it.

Gary Bergman
11-23-2002, 06:55 PM

11-23-2002, 08:07 PM
Believe its what those in the old country call fiberglass. Glass reinforced plastic. Nothing in the world wrong with it-some think they deserve a place at the head of the snob line cause they own or can make a wood boat. Truth be told the skills and knowledge needed to be an expert fiberglass technician of the type who can build plugs and molds probably exceeds that of most of those on this forum that profess wood as the apex of boat building.

11-23-2002, 08:24 PM
I see fiber@la$$ normally referred to as FRP = Fiber Reinforced Plastic -- guess glass reinforced plastic is possible, but seems a stretch. I'll ask Dave in a bit - he's on the couch checking the insides of his eyelids for hairline cracks :D

At any rate, you'll be hard pressed to come up with a better one than Donn's ;)

Regards -

11-23-2002, 09:08 PM
glass/fiber reinforced plastic
or gamma ray pulse?

Gary Bergman
11-23-2002, 09:28 PM
I sorta thought it was a european phrasing of flubberglass cuz I always see it in Watercraft and Classic Boat..."rub..I own and have built both fiberglass and wood. You are sadly mistaken

Hugh Paterson
11-24-2002, 08:31 AM
Steve Hmmmmmm I could say what a bunch of snobs but I wont...... honest :D Bill got it, Glass reinforced plastic, polyester resin reinforced by chopped strand matt or in more expensive models woven rovings and a variety of other exotic materials, the term fiber reinforced plastic is more common in some parts of the world, kevlar and carbon fibre are among some of the more "exotic" materials in common use. I have a certain "fondness" for the stuff because I work with it on a regular basis, most of my customers want a "Goo" boat simply because they are cheaper and quicker to build, (less overheads more fun). Much as I hate to say it gentlemen, if it was not for plastic boats, my sport of sailing would not be as pouplar a pastime as it is today. Oh and and not just in boatbuilding, if it wuz a choice between a BMW car with a steel body tub or a TVR with a composite frp bodyshell, I will opt for the TVR (better than sex?) :rolleyes: Dont see any wooden boats in the Americas cup either (shame) Har Har, Yes I await the Fallout, and I fully expect the sky to fall on my head any moment.
Shug the FRP technician, (who also owns and repairs wooden boats) When I can find them! ;)

11-24-2002, 09:19 AM
Better than sex? Hmmmm. Okay we will no longer refer to a woody. It'll be a frppy from now on. 10-4?


11-24-2002, 10:36 AM
Originally posted by Dutchrub:
Truth be told the skills and knowledge needed to be an expert fiberglass technician of the type who can build plugs and molds probably exceeds that of most of those on this forum that profess wood as the apex of boat building.The ARK was built by an amateur - the Titanic was built by professional expert technicians.

Scott Rosen
11-24-2002, 12:11 PM
I don't care how much or how little skill it takes. Grp boats have different smell, feel and sound. And I don't like it at all.

11-24-2002, 12:56 PM
I second Scott's reply. They are just a different feel. And IMHO, it's better.


Ian G Wright
11-24-2002, 12:57 PM
Originally posted by Hugh Paterson:
if it was not for plastic boats, my sport of sailing would not be as pouplar a pastime as it is today. ;) What a wonderful picture you paint, only wooden boats, the pastime of sailing unpopular, so, many gaps in marina berths, prices of berths and moorings falling, space on the water, rivers and bays free of mooring buoys leaving room to anchor, if only,,,,,,,,,


Hugh Paterson
11-24-2002, 01:34 PM
Oh dear, I swear this cloudbase is getting lower,(well this is Scotland), or is it a mist clouding eyes, maybe tears of laughter and all that. Ian your sailing in the wrong part of the UK, if I go much further than NW of Arran, somedays I count all the boats I "bump" into on 1 hand, Then again maybe its the smell of Styrene that oozes from my pores that keeps everyone at bay :confused:

Oh and by the way I built my new tender today, the replacement for the Rubber duck, only 8ft long in smelly grp. Total cost so far 82, the Mahogany for the gunwhale and thwarts will cost more I suspect? If I pull it out the mould on Monday I could float it on Tuesday. Anyone want a race building the same boat in clinker/ply?

11-24-2002, 08:53 PM
Hugh -your preaching to a bunch of bigoted slobs who would rather dream it than do it - course we all like the romance of the wooden boat, but how many are truly out there making a living ?everythings got its place, but to be realistic the golden days of wooden boats, planes, cars and soon to be houses is over.

Gary Bergman
11-24-2002, 09:39 PM
So how come this always turns into a'my dog's bigger 'n your dog' thing? No other wat to blow off the testosterone?

[ 11-24-2002, 09:40 PM: Message edited by: Gary Bergman ]

Wild Wassa
11-24-2002, 09:43 PM
GRP, getting really personal.


Peter Malcolm Jardine
11-24-2002, 09:53 PM
I always wonder about people who come to this forum to tell us fibreglass is so superior and the people who build them are so much smarter and so on. I don't really care. I like wooden boats better and I come to this forum because it says "WOODENBOAT" right at the top... just look up there and see. it doesn't say "FIBREGLASSBOAT" or "KEVLARBOAT" or "ALUMINUMBOAT" or.. well you get my drift. Hey.. don't get me wrong,if you want a fibreglass boat thats great... go get one. Join a fibreglass boat club, get some plastic dinnerware, and a polyester leisure suit. Fill yer boots. Buy some plastic martini glasses and tout the superiority of fibreglass as you slowly sink into your injection molded resin deck chair. Wash your boat with a nylon bristled polypropylene handled deck brush.Watch the marina help polish your boat with polymer based wax,and wipe down the cockpit cushions with Armor-all.Use plastic parts recycled from melted down sprite and Crush orange bottles.Line your cabin with laminate covered genuine simulated teak panels. Feel the flex of fibreglass under your feet in a chop.Name your children "Delrin" and "Nylonia" Yes indeed. but not here. nope. This says "WOODENBOAT FORUM" and WOODENBOAT magazine. The magazine for WOODENBOAT owners, builders and designers. Its does not say fibreglass, plastic, grp, tupperware, or anything like that. Nossir. Not here. Not now. Not ever. :D

[ 11-24-2002, 10:51 PM: Message edited by: Peter Malcolm ]

Mike Field
11-25-2002, 12:29 AM
Attaboy, Peter. A definitive statement of what the Forum's about. I think that that should be about the last word on the subject.

Hugh Paterson
11-25-2002, 04:36 AM
Ouch, I like it Warren, getting really personal, I think I shall play with a wooden boat today, just to get a dose of sawdust fer a change. Anyone want to help me rip caulking out, to be replaced (in part) with splines, messy bloody job!
All fingers-n-gunk.

11-25-2002, 09:01 AM
I can't resist stirring the pot a bit ;)

I have every faith that the dyed-in-the-wool, card-carrying, wood-is-good dedicated traditional wood boat fans here who are fortunate enough to possess one of these gems of human ingenuity and craftsmanship have them rigged with natural hemp or manila ropes (no plastics like nylon or polypropylene) controlling egyptian cotton or cotton duck canvas sails (none of the icky plastic stuff) and that all the blocks and winches on your wood beauty are constructed with bronze, babbit, or lignum vitae bearings and thrust bearings so that they have none of the horrible plastic stuff such as delrin or teflon that the newfangled gear has. One must be true to one's convictions about "there is NO PLASTIC ON MY BOAT!!" I expect that this also extends to your foul-weather gear and your cooler for your beer, too.

Down with technology! Luddites unite! :D :D

Ian G Wright
11-25-2002, 01:17 PM
Originally posted by mmd:
I can't resist stirring the pot a bit ;)

I have every faith that the dyed-in-the-wool, card-carrying, wood-is-good dedicated traditional wood boat fans here who are fortunate enough to possess one of these gems of human ingenuity and craftsmanship have them rigged with natural hemp or manila ropes controlling egyptian cotton or cotton duck canvas and that all the blocks and winches on your wood beauty are constructed with bronze, babbit, or lignum vitae bearings and thrust bearings Well yes,,,, pretty much. I'm thinking of removing the engine in the next year or two also, as long as you have no objection?
The new tender, sadly, is grp, but only until I can find a building shed for a new wooden pram. I cheat of course, the cotton sails stay at home most of the time and dacron (the cream with brown stiching and 18inch panels plus hand worked brass cringles) are used most of the time,,,,, Standing rigging is all hand spliced and served, no winches naturaly,,,,,,
I own but never use a set of Musto Ocean something Oilies. I prefer a Barbour Longshoreman smock, Waxed cotton you know, waterproof and not sweaty. Never seen the point of deckshoes. My normal sailing footwear is carpet slippers though I have boots for when it rains. I find a so'wester is a good wet weather hat, I like to navigate with charts and a pencil and I drink rum.
How steriotypical is that?


11-25-2002, 01:46 PM
God love ya, Ian! :D I knew I could count on you to carry the true flame. And the mental image I now have of a jolly tar underway in his traditional British inshore craft with a smile on his face, tiller in one hand and a rum in the other, garbed in traditional slicker 'n' sou'wester and shod with bedslippers will now forever be one that tints my view of how boating should be done.

ion barnes
11-25-2002, 03:20 PM
Hey Hugh! My eyes sure bugged out at your post and I concurr with your thoughts. I too like wooden boats and have a small kayak in progress, however, I like fibreglass also. Why you may ask? Well, I have a TVR Vixen + parts and would not trade for a MB or BMW. As for the rest of you, I think you should refrain from sheathing your creation in epoxy and glass or using carbon reinforcment. Also,when I walk the wharves, I am hard pressed to find a wooden dinghy attached to a wooden boat. Must be an economy move. I am very much drawn to a wooden dinghy of delicate scantlings. But I still like FRP\GRP\whatever

George Roberts
11-25-2002, 03:54 PM
One day I will need to purchase a wood GPS.

Wood has many good uses. Building boats is one of them. A bit of metal, a bit of GRP often make a better boat.

Ian G Wright
11-25-2002, 04:55 PM
Originally posted by mmd:
traditional British inshore craft .Inshore Craft? A Vertue? Inshore? Fit for any ocean is a Vertue,,,,,,,, though some skippers might not be.


11-25-2002, 06:53 PM
Man, I can't take a stride without stepping in crap today. :mad: Ian, in my area, in local terminology, any vessel less that fifty or so feet long is termed an inshore craft, even though they regularly go fifty or a hundred nautical miles offshore in February. I didn't mean to impune the seaworthines or any other -iness of your vessel. The term is not meant derogatorily. Sorry if I offended.

Peter Malcolm Jardine
11-25-2002, 07:04 PM
Okay what I really meant was... even if fibreglass boats were better, I would still have wood. The only other boat I see myself having is steel. but it was all in fun. :D :eek: :D

11-25-2002, 08:14 PM
ALUMINUM MAN...ALUMINUM!..lets face it....beats everything else..in every way.... tongue.gif

Ian G Wright
11-26-2002, 05:44 AM
Originally posted by mmd:
Sorry if I offended.You didn't,,,,,,,,, some people just don't understand about Vertues. smile.gif smile.gif


11-26-2002, 07:20 AM
"...GRP !..."
...is the sound made by a passenger, hanging over the rail in a heavy sea.

11-26-2002, 07:32 AM
I have some Nylon and some polyester ropes. But the electric cables are sheathed with rubber, as they should be. The sails are actually a cotton/Dacron mixture.

Now, what LFH called it was......

........Frozen Snot.

11-26-2002, 08:05 AM
Ok, all knowing and humorous ones - since LFH was good enough to give us his thoughts on fiberglass, what would you call carbon fiber???

<drawing bull's eye on forehead and ducking...>

- M

11-26-2002, 09:13 AM
Carbon fibre - a wonderful engineering material that is suffering from way too much hype. I suppose in the LFH idiom it would be frozen coal miner's snot.

11-26-2002, 09:15 AM
As I was getting ready to head out the door, I thought what about Freeze Dried Snot???



11-26-2002, 05:06 PM
One of my favorite web tools is Acronym Finder. Here's the definitive list:


Peter Malcolm Jardine
11-26-2002, 05:31 PM
Hmmm from whats Grp to freeze dried snot... imagination is not lacking here anyway.. :confused:

Steve Lansdowne
11-26-2002, 06:27 PM
Funny how a brief mention of GRP on this Forum leads to endless tangential responses long past the basic answer to the question posed. I think many of us just like to type!

11-29-2002, 01:33 AM
WOOD SUCKS! FRP is the future! *DUCKS* *hey guys i dont think you can do that with a chisel...*

Hehe i dont think anyone here 'hates plastic' in that sense. I think what they dont like are the overpriced factory produced cookie cutter boats.
Heck most of them praise glass sheathing. I dont see a lot of them professing a desire to do what spray did with hand tools. As in all things i think we all assume prejudices in others that arent actually there.

It is kinda funny though. You dont see wooden boat fans hanging out in "Fiberglass boats" magazine forum lashing out at evil 'traditional fiberglass boatbuilders". Hmmmm.. troll?

11-29-2002, 05:45 PM
We don't care what the snot-lovers say--the polyestermites will git 'em in the end.

As for the skill it takes to build a snot-boat, I'll grant that it takes some to build the plug, but then you can teach any stumblebum off the street to lay FG mat in an hour and pay him coolie wages. That's a major reason so many companies have made the switch. There are only a few whose products one would be proud to own. A wooden boat building apprentice takes years to learn his trade, and when he becomes a journeyman you have to give him a decent wage to keep him. And there's an excellent chance that you will be proud to own what he builds.

[ 11-29-2002, 06:07 PM: Message edited by: Bayboat ]

11-29-2002, 06:17 PM
Ok, here's my 2 cents worth.The limey likes glass, the cannuck insults the limey. If it weren't for yanks and glass, we couldn't afford a dinghy. The more involved in an activity, the less it costs per person to participate. Simple law of supply and demand. I'm eternally grateful that there are glass boat people out there to buy equipment, and powerplants, generators, build more marinas, etc. I love wood boats. It's just my d*** opinion, and my money to buy the thing. They are an ongoing pain in the a**. I know this and still participate. I fix more than I use. I drive a Rolls-Royce, and it's the same story. It's never finished, always painting, tuning, replacing etc- just like the wooden boat! But a stinking Sushi mobile reeks of chemicals, and cost more than the Rolls to operate. And then to add insult to injury, there ain't no conolly leather or circasian burl walnut interior trim! That's why I like wood boats, Rolls-Royces, old houses. It's not convenience, it's quality craftmanship of a kind that no longer can be duplicated except by the likes of a few fanatics like us. Fibreglass is for playtoys, wood is for works of art.


Ken Liden
11-30-2002, 10:40 PM
I was told by a factory rep that it means Glass Reinforced Product.

12-01-2002, 12:18 AM
OK, OK. I'll come out of the closet. I admit I do designs for boats to be built of this "other stuff", too. redface.gif Here's the gist of it, as I have come to understand it:

FRP - Fibre Reinforced Plastic consists of two-part thermo-setting plastic resin reinforced with any variety of fibrous materials ranging from shredded cotton, hemp, glass, carbon fibre, Kevlar, etc., etc., in matrix with the plastic.

GRP - Glass-fibre Reinforced Plastic consists of two-part thermo-setting plastic resin reinforced specifically with drawn glass fibres in matrix with the plastic.

... if I do wood boat designs too, does that make me bi-structural? :D

[ 12-01-2002, 12:19 AM: Message edited by: mmd ]

12-01-2002, 06:24 AM
Another 2 cents: when you go to a big marina you see hundreds if not thousands of white things that look like somebody's bathtub. They all look dirty and they all look faded, even the new ones. Then you find out what people paid for them and you ask what the hell for? Two pieces of molded plastic glued together with an engine and a couple of seats? Maybe they don't leak as much as our boats, but where do they go after ten or 20 years? To the landfill or the bottom of the sea? It would be interesting to note how many 20, 30, or 40-year-old glass boats are still in use. Seems to me beyond a certain age a wooden boat is easier to maintain in pristine condition. And then there's the matter of looks.

Eric Sea Frog
12-01-2002, 08:53 AM
Somebody else's bathtubs. Pulling the words out of my mouth!
No little job to dispose of and burn those bulky plastic hulls, I guess. Not environmental friendly. Cars at least get recycled.
Now, let's come clean, that stack of aluminium tubes against the wall of my room isn't a portable japanese organ, it's a folding kayak in the making, to be skinned with 13oz nylon.
No much better, that open book on the table tells about an Atlantic crossing aboard a skin on frame sailor covered with oxhides... tongue.gif


12-01-2002, 01:13 PM
Doc- you're dead right. There is an undeniable pleasure in appreciating the degree and quality of craftsmanship that can no longer be easily attained. I own a 1964 International Travelall that is neither fast nor plush, but its indestructible inline six cylinder and 4WD running gear are built to withstand time and use. I would spend 20 grand in a heartbeat to repair this classic rather than buy one of these laughable "Sport Utility Vehicles" soccer moms are so fond of. Form MUST follow function, but when the function is executed in such a brilliant manner (as with a finely crafted wooden boat beating to weather or my beloved Travelall), beauty of the form is inherit. It is a waste of time to try to relay this point to someone who values convenience over intimacy with their boat. A FRP boat is more akin to dropping your kids off at daycare, while a boat built of wood is like homeschooling the tykes. Both have different values to different people, and should be respected as such. This just happens to be a Wooden Boat Forum, with a wonderful bias towards the effort and subsequent rewards involved with boats of wood.


Peter Malcolm Jardine
12-01-2002, 01:37 PM
Oh Doc.. you are a glutton for punishment drivin a rolls... :D Beautiful car... I want one, but you need to be handy... or rich. What year is yours?

12-01-2002, 03:25 PM
Glass - Reinforced Polyester.

Epoxy-composite [whether glass, carbon or other fibre] construction is not called GRP.

"Plastic" is today a imprecise term used more in the sense of "anything made by man" than in any precise sense.

Literally, a plastic material is a material capable of undergoing a kind of deformation known as plastic deformation, which is a continuous deformation. Modeling clay is one such material.

Hugh Paterson
12-01-2002, 08:34 PM
Argggghhhhhhhh, Tell me the Doc didnt call me a limey :eek: I am a haggis hunter of some repute and there fore SCOTTISH and proud of it tongue.gif
Keith, sorry to dispel the myth, but my grp snot boat is 30 years old, well one of them is, its still got its 1st engine, it needs a paint job because its tatty looking but NO osmosis and it growls with the best of them at around 40 knots in the right conditions, oh and the best bit is I only paid $2000 for it the year after the engine had a $4000 rebuild. I reckon I should get another 5 years use out of it without throwing anything else at it but gas and a tin of paint.
If only I could say that about the wooden boats in my wee fleet. They need lots of TLC to keep them looking pristine, and spare time is somthing I am short of, but hey 20 years and I can retire and play with my own toys, If the sky does not fall on my head before then ;) Bugger it I will maybe stop working a 55, if SWMBO lets me :D
Mean while happiness is snot boats, except when I am out fishing in my clinker dinghys with two rods the dog and a crate of beer for company.

12-01-2002, 09:37 PM
Originally posted by Skillet1927:
A FRP boat is more akin to dropping your kids off at daycare, while a boat built of wood is like homeschooling the tykes. Both have different values to different people, <snip>
ChrisWow. there's an analogy that hung me up. I like it. :D