How to Work Fiberglass Right

[rspears]

So there are a lot of us working with fiberglass bodies, accessories, and parts that need repair, modification or total re-work and it seems that there are a lot of ideas being tossed out as "The Gospel" for what's right and what's not. I picked up my approach by talking to a guy with 40+ years of paint & body, much on glass or using fillers the right way for long term stability, and reading tech articles and books on glass working. That said, my way may not be right for everyone, and simply may not be right!!

I'm posing a question to the guys out there who have been working glass through the years, and who know what's right and what's not without having to ask anyone for suggestions. We have a few guys on here who earn their daily bread slinging resin on mat, and we have a few more who have been building/repairing glass boats, car bodies, consoles, etc, etc, for many years. My thoughts are that it would be a big value to have some true expert input on something like 1) repairing a hole in a panel, 2) repairing a rolled edge, like a door jamb, 3) extending a panel, like a door or hood edge that may need an added 3/4" to close a gap with the jamb, 4) molding a part where one has or makes a mold, lays up mat & resin and then pops it out after curing to finish, maybe relatively small parts, 5) making a panel from scratch, like a Deuce hood side or... that needs to be flat, and stay flat, and maybe free forming with fleece the right way ?

Any true Glass Master's out there who are willing to share? Looking for some good, step by step ideas on how to do the work and thinking it might save some of us some grief as time goes by.

[36 sedan]

Good idea Roger, I would buy this book too!

[pat mccarthy]

first off you need to know what your fixing glass or SMC sheet molded composite

[rspears]

first off you need to know what your fixing glass or SMC sheet molded composite

Pat, for the lions share of what we see here I'd say we're dealing with hand laid fiberglass if it's a quality product, and chopper gun fiberglass if it's lower quality. I don't think that I've seen any SMC sheet molded composites being used for street rod bodies or components, but I could be wrong. For purposes of this thread let's assume Fiberglass, not composites as the title states.

[pat mccarthy]

Pat, for the lions share of what we see here I'd say we're dealing with hand laid fiberglass if it's a quality product, and chopper gun fiberglass if it's lower quality. I don't think that I've seen any SMC sheet molded composites being used for street rod bodies or components, but I could be wrong. For purposes of this thread let's assume Fiberglass, not composites as the title states.

well if your taking hand laid glass or chopper glass that s fine but over the years guys have been fixing what they were thinking was glass when it was smc .what you are looking for is on west systems web pages and making body plugs and making bodys and fixing holes look at any thing on the west systems under jon s . i fixed glass for many years and smc work on many thing s over the years did finish work for jon at one time seen him make many things one of the best i seen. pick a subject and maybe i can put a finer point to how i would do it

[Henry Rifle]

. . . hand laid fiberglass if it's a quality product, and chopper gun fiberglass if it's lower quality.

Dang, Roger - that hurts!

[rspears]

well if your taking hand laid glass or chopper glass that s fine but over the years guys have been fixing what they were thinking was glass when it was smc .what you are looking for is on west systems web pages and making body plugs and making bodys and fixing holes look at any thing on the west systems under jon s . i fixed glass for many years and smc work on many thing s over the years did finish work for jon at one time seen him make many things one of the best i seen. pick a subject and maybe i can put a finer point to how i would do it

Pat, did you read the first post to the end or stop at the title? There are five different subject lines stated as suggested starting points there, but maybe that's not what you mean by "pick a subject"?

Dang, Roger - that hurts!

Jack, not trying to throw rocks, just seeking some knowledge.

[pat mccarthy]

[QUOTE=rspears;524717]Pat, did you read the first post to the end or stop at the title? There are five different subject lines stated as suggested starting points there,.. maybe that's not what you mean by "pick a subject"?...... yes holes .door jam . what first . body plug . fixing a poor built body what??? you can not do much for a poor body parts that are thin and a air cure lay up out in the sun parts move so that ones been done

[shine]

chopper gun or hand laid means nothing. type of resin is all that counts. there are many different tiers of resins. just like paint there is good better and best with 50 qualities in each. epoxy is the upper tier, vinylester then polyesters. i use epoxy resin for any repairs , vinylester for any mold work , polyester for things like speaker boxes and such. the key to resin work is cure. best way is to wrap in black plastic and set in the sun for a while. exposed to higher temps than normal.

[lamin8r]

chopper gun or hand laid means nothing. type of resin is all that counts. there are many different tiers of resins. just like paint there is good better and best with 50 qualities in each. epoxy is the upper tier, vinylester then polyesters. i use epoxy resin for any repairs , vinylester for any mold work , polyester for things like speaker boxes and such. the key to resin work is cure. best way is to wrap in black plastic and set in the sun for a while. exposed to higher temps than normal.

Shine,,I know you have had experience with glass,too,,as has Pat.. We all have different methods,and different ways of approaching things with this stuff.. I was taught in the late 70's,by one of the better guys in the industry,,who did his apprenticeship in a boat factory..He went on to become a leading light in boat repair in West Auckland,,and was actually known by many,as the pox doctor,,cos of his experience in repairing polyester yacht hulls,,some of which had spent a year or two in the tropics..Anyway,, my forte has been,for several years,repairing a lot of automotive parts,,including SMC truck fronts,and bumpers,,and the regular fibreglass truck hoods,,from Kenworth,Mack,Freightliner,etc.. All of my work is done with polyester..I have no problem with it,,and I would prefer to do my repairs,,where possible,with what was used originally.. I have a few dirty tricks up my sleeve,for SMC,,and while it's not 100% foolproof,,they still last..
I use polyester for making molds,,with a good vinylester tooling gelcoat.. As a rule,,I don't even have epoxy in the shop,,but do get tired of grinding out crappy epoxy repairs,from inside some panels laid up in poly... ,,that look like they have been whacked in with a mop,and 4 times more resin than necessary..
I usually set my layups off with an infra red lamp,then leave them to finish.. most of my stuff,that I do in my molds,stays in the mold for two days,or so before I pull them.. Hey,,the black plastic works well,too.. have speeded up the mold curing with that method..
Gunna leave it at that,cos I don't think we need to have too many disagreements in this issue.. One of the reasons I hang back from these threads,,is,that you can guarantee there will be a few differences of opinion..
Gotta say though,,most of the chopper gun layups I have seen,,are either good,,or real bad,,such as the Deco Rides Lincoln Zephyr bodies..Ya need an experienced operator,with his mind on the job,,and a good guy on the roller to finish..

[36 sedan]

I want to to make a piece for the top of my grille to the radiator to keep the air from going over the radiator. I have fashioned a fair fit from a plastic trash can lid, how can I make this from fiberglas or some other material that will hold up?

[pat mccarthy]

I want to to make a piece for the top of my grille to the radiator to keep the air from going over the radiator. I have fashioned a fair fit from a plastic trash can lid, how can I make this from fiberglas or some other material that will hold up?

the cost of one in glass will be much more then getting sheet of tin and building it

[36 sedan]

My tin skills are poor, this has compound curves. I'm afraid I've wasted more on tin already than I could have made it from fiberglas.

Do I need to make a reverse mold out of plaster first, or can I lay over the plastic lid?

Are there other materials besides fiberglas I should be looking into to make this from?

[rspears]

My tin skills are poor, this has compound curves. I'm afraid I've wasted more on tin already than I could have made it from fiberglas.

Do I need to make a reverse mold out of plaster first, or can I lay over the plastic lid?

Are there other materials besides fiberglas I should be looking into to make this from?

If you've got a good fit with the plastic lid, and if you can accept that the fiberglass piece is going to be slightly bigger since it's laid on top of the fitting part, then simply wax the plastic with a good coat of wax and lay the glass mat on top. Let it cook off for an hour or so and it will pop off easily and you can then sand it smooth, hit it with a coat of filler and it's done.

[lamin8r]

If you've got a good fit with the plastic lid, and if you can accept that the fiberglass piece is going to be slightly bigger since it's laid on top of the fitting part, then simply wax the plastic with a good coat of wax and lay the glass mat on top. Let it cook off for an hour or so and it will pop off easily and you can then sand it smooth, hit it with a coat of filler and it's done.

There is no reason,for a fiberglass piece to be larger,Roger,,since a mold is usually taken off the outside surface of that part..If you take a mold from that part,,what comes out of the mold will be the same..... Unless,of course,that the plug is taken out of the mold,,before the mold has finished curing,,in which case,,the mold will shrink slightly..And,,it is very hard to take a mold off a thin plastic item,,or,,as I call it,,a ''street weight'' fiber item..They need to be braced well,,and build the mold slowly,,a couple of layers of glass at a time.. AND,,,DON'T use too much gelcoat in the mold,,as if it's too thick,,it will shrink from the mold as it dries..
For a small item,,I will make my mold about 3mm thick,,built up over a couple of days,and a week of curing..minimum..