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Topic: Need an education on fiberglassing (Read 792 times) previous topic - next topic

Need an education on fiberglassing

3 years ago someone backed into my RV engine door and quarter panel.  Got the door fixed on the outside but apparently there was some damage to the fiberglass that is attached to the lower metal frame of the engine door.  My door tilts out from the top two latches and then raises up and out of the bottom pivots out of the way for engine access.



Should I take it to a professional or attempt it myself??
How would you go about fixing it?

This is looking right to left along the bottom of the door as it is tilted out



2000 GV320 4010 build #5712  2019-?
1999 Bounder 2000-2008
Bardstown, KY
🥃The Bourbon Capital of the World🥃

Re: Need an education on fiberglassing

Reply #1 –
Lots of YouTube videos that show you exactly how to do it. I use epoxy resin for everything and multiple layers of cloth, never mat. Ebay or West Marine and others will have all the stuff. Epoxy sticks to everything, has very little smell and you can wash it off your hands if you get some on you. It's still work getting it off.

Laminating resin, not casting or bar top.

Videos here: https://www.youtube.com/results?search_query=fiberfglass+with+epoxy+resin
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Need an education on fiberglassing

Reply #2 –
If you have any experience with fiberglass, I think it is something you can do. It appears to be bowed in slightly at the bottom and would need to be taken off the back of the coach. It should be clamped to pull the bow out and made flat again. You may need to grind the old fiberglass out in order to do this. Hopefully the outside finish is okay and you won't have to do anything to it. My experience with Fiberglass finishing is limited so my opinion is limiting also...... Good luck.
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Lynn & Marilyn Sickel
Tollville, AR
1997  U320  40'
2021 Chevrolet Silverado pickup
Motorcader  17257

Re: Need an education on fiberglassing

Reply #3 –
From the picture it looks like it has been repaired and the new piece has torn loose. First I would
get it back in place and then cut out the torn pieces. If it has been repaired I would use
cold cure epoxy with cloth as epoxy is stronger than glass but more expensive. Grind all the old glass
where you are going to add the new material. To cut it out I would use a zip blade and a grinder disk
to clean it up. Use a face mask.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Need an education on fiberglassing

Reply #4 –
Use a paint respirator and overalls if grinding. Laminating epoxy runs me about $85 or so per gallon so not much over polyester resin. Cure time depends on type and hardener. gallon laminating epoxy resin - Google Search

On some impossible black water tanks that resisted all repairs, I used fiberglass cloth with epoxy to seal the big crack and it never leaked a drop. It resists gasoline or diesel so you can make a tank out of it.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Need an education on fiberglassing

Reply #5 –
Start with small pieces and layer it on with each piece getting a little wider in diameter. Let each layer dry and sand lightly before applying the next. Cut your pieces in circles, not squares. That prevents the fibers from pulling out as you apply the resin with a brush. When mixing the resin, err on the side of too little catalyst, it's better for it to dry too slow than too fast. Don't ignore the curing temperature recommendations, it's really important.

Source: I fixed Kevlar canoes for years
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Need an education on fiberglassing

Reply #6 –
Tommy grinding fiberglass is no fun. Heck ya you can do it, but you might find the guy who does this every day at your local marina may do it for less than the materials you will be purchasing and having product left over. West Marine makes magical products, you wont be disappointed or be rerepairing. Talk to the boat guy and have it removed for him. Very likely he will come to you or have a small shop to do repairs.
Scott

Re: Need an education on fiberglassing

Reply #7 –
FWIW Laminating resin is resin with no wax.  Why wax?  So the resin is protected from the atmosphere for a full cure.  Or you can spray the surface with polyvinyl alcohol to temporarily seal the surface for the full, non-sticky cure.
Aren't you glad you asked?
Art
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Need an education on fiberglassing

Reply #8 –
PVA is great stuff. The guy at the boat shop will have a spray bottle with a nickel worth of product in it. Not to worry though it will still cure out after awhile.

Re: Need an education on fiberglassing

Reply #9 –
Quote from: dsd –
PVA is great stuff. The guy at the boat shop will have a spray bottle with a nickel worth of product in it. Not to worry though it will still cure out after awhile.

I settled on using polyester resin for my repairs.  With either choice wax-less laminating resin is the way to go if you intend to lay up more than one layer of cloth and resin.  If you're doing finish work, you can apply the gel coat last and cover it with a coating of PVA.  For me, having wax around is just one more thing to go wrong.  Plus, paste wax is the classic mold release if you want to make a part but PVA works just as well if not better.  And while PVA can be removed with soap and warm water, it is tough enough to withstand brush applied gel coat in your mold.

Art
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Need an education on fiberglassing

Reply #10 –
Art it funny how we talk about things we know but dont give the reason they are so important. Polyester vinyl resin is great stuff. Layers are put on top of each other they literally bond together. They become one. If the outside of the glass is exposed to air it doesn't cure so that It can bond to the next layer. They become one. Otherwise they don't bond together but they adhere to each other. This is two parts that are stuck to each other, not bonded, not one piece. Doesn't sound like much but it really genuinely is. Whenever you put resin on top of a cured part it is just stuck to it by adhesion, it is not bonded to it. And back full circle to why I like epoxy with higher Adhesion characteristics when repairing old fiberglass

Re: Need an education on fiberglassing

Reply #11 –
Quote from: dsd –
Art it funny how we talk about things we know but dont give the reason they are so important. Polyester vinyl resin is great stuff. Layers are put on top of each other they literally bond together. They become one. If the outside of the glass is exposed to air it doesn't cure so that It can bond to the next layer. They become one. Otherwise they don't bond together but they adhere to each other. This is two parts that are stuck to each other, not bonded, not one piece. Doesn't sound like much but it really genuinely is. Whenever you put resin on top of a cured part it is just stuck to it by adhesion, it is not bonded to it. And back full circle to why I like epoxy with higher Adhesion characteristics when repairing old fiberglass

I'm given to understand by my reading before I began repairing my roof, that without the wax polyester resin stays open and will chemically bond to the new layer.  Yes there are time limits involved that are not intuitive, and yes I give a wipe with acetone to make sure I have chemical hooks. but so far all has held both on the roof and the fuel bay door.  This fall after the heat and humidity breaks I'm going to glop on more epoxy gel coat on the bay door I repaired with polyester resin and call it done.  What is there has withstood both weather and use without any issues.

My go to source for all things resin is :  Fiberglass Cloth

I find them more interested in filling my order than making me feel good and they expect you to do the reading.

Art

1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Need an education on fiberglassing

Reply #12 –
Quote from: dsd –
Tommy grinding fiberglass is no fun. Heck ya you can do it, but you might find the guy who does this every day at your local marina may do it for less than the materials you will be purchasing and having product left over. West Marine makes magical products, you wont be disappointed or be rerepairing. Talk to the boat guy and have it removed for him. Very likely he will come to you or have a small shop to do repairs.
Scott

Decided to take your advice!  I'm letting the professionals handle it.  Thanks for all the info and your time from all who responded.

2000 GV320 4010 build #5712  2019-?
1999 Bounder 2000-2008
Bardstown, KY
🥃The Bourbon Capital of the World🥃

Re: Need an education on fiberglassing

Reply #13 –
Quote from: Tommy D –
Decided to take your advice!  I'm letting the professionals handle it.  Thanks for all the info and your time from all who responded.

Smart man.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.