i'm planning to glass my first board. necessary supplies (polyester resin, mekp catalyst) are available and i feel quite comfortable with the process. but there is one concern: as i live in a landlocked european country temperatures might be an issue. the shaping room has no windows. therefore i want to do the glassing in the garage. there, i won't have a problem with air circulation. but i can't control the temperature in the garage. during winter time we expect an average temperature of 40-50 F.
- will such low temperature have an influence on the glassing process? even if resin is stored and "warmed-up"?
- resin supplier recommends 65 F+ for the glassing. may i influence the hardening process by changing the ratio resin/catalyst?
any advise that my first glass job doesn't end in a mess would be much appreciated.
50 is much too cold, IMO. boosting the catalyst amount works, up to a point. I have tried glassing in temps below normal range. Usually leads to a mess. Is there no way to run an extension cord to the garage, and set up one or two electric space heaters? I’ve done it, and it makes all the difference.
I’m just doing a board in 40-50° and I would recommend to you to heat the room if possible. It works, but is much more difficult. The resin feels really weird and doesn’t saturate the fibres the same than normally. Yesterday I made the top hot coat, but I ended up with a messy surface. Well on top I don’t care that much, but the bottom will be done in a heated room otherwise I have to sand really long…
My shop becomes an ice cube in the winter living in the mountains of Maryland. Here’s what I do.I fill up a container (cooler or 5 gallon bucket) with hot water to bring to the shop. As soon as I get to the shop, I crank up a torpedo heater and set my resin in the hot water. I get all my prep work done while waiting for things to warm up. By the time the shop and glassing room warm up to 65-70 degrees, the resin is warmed up enough to glass. Turn off the heater and get to work. The resin kicks before the room cools. I have done plenty of glass jobs ranging from standard glass jobs to hot coats, gloss coats, and repairs without problem. These are boards I do for myself and surf and to this point have had no problems with brittle resin damage.
U.V. resin or purchasing some of the powder (less shipping cost) is absolutely your best bet. As long as you can glass it then take it out in the sun it doesn’t matter if there is snow outside. In fact the reflection of snow would probably make for even more UV rays and the board would cure even faster. In Southern California, where i live, I glass indoors than have an outside curing rack. The boards are fully cured in 5-7 minutes most days.
Before UV resin was around I glassed boards in cold weather (50 degrees) by heating up the resin. You can carefully microwave it for a few seconds at a time or use a handheld hair dryer to warm it up. The viscosity will get thinner making it easier to saturate the fiberglass, and the kick off time will be relative to the STRENGTH of catalyst hardener you have (it is available in different strengths).
I even noticed way back when, that the container that you have the catalyzed resin in makes a difference. In a metal container, once the catalytic action begins, the can accumulates heat faster whereas a paper bucket loses the heat. The first few times using a metal bucket resulted in resin kicking off unexpectedly fast! Later on I actually used this as a tool when faced with very cold weather and a hurry up order.
For catalyzed resins you can use this general guideline in regards to curing. The quickest conditions resin will cure is 1. low humidity/hot 2. high humidty/hot 3. low humidty/cold 4. high humidty/cold.
But again… being that you are a beginner, and with the advent of UV resin. It just doesn’t make any sense whatsover not to go this route.
…winter here is very cold and with too much humidity.
Polyester resins kicks always not epoxy ones.
I have AC units but still very difficult to raise the temp.
Main problem is with the gloss coat.
With the lamination step, most resin brands do good; sometimes, if its too cold, around 6ºC/100%humidity, you would perceive kind of a white blush. That s not happen always and depends on the brand and model of the resin too.
If that occurs, after the stratification, pass a hairdryer and the blush dissapear.
Do not put too much MEKP or you ll brittle the resin.
Thanks for all your replies. I think it would be the easiest to find a heated place to avoid a mess with my first glassing job. or wait until next sommer to get my board finished... which is of course no option! :-)
alright! I need to jump on this train again and do not want to harass people with another thread on this! I will do my first polyester glass job with MEKP tomorrow in the work space at my grandpas! I have 3 questions though…
1. What is the minimum Temperatur I need for a solid glass job? like really the minimum? 60-65 F should work?
2. and at what resin/hardener mix should I work? 1% or more?
If you are serious about this; start using UV. If you can’t walk it out in sunlight, build a UV box. It’s worth the time and trouble. UV will give you the best and most consistent results. Never heat poly resin. That is an Epoxy trick. Not poly. Get that room up to 70 degrees and keep it there until your lamination has set.
I would start with the % of catalyst recommended by the maker of the polyester resin, try to get the information from the supplier or manufacturer. I am doing epoxy now, but when I had low VOC poly and regular gloss poly around they were catalyzed at different rates. The gloss I had came with SA (surfacing agent or ‘wax’ for sanding ) already added by the supplier.
Congrats on getting the board to the glassing stage! -J
helterskelter-
Yes, the sudden increase in temperature made the resin kick fast. You are better off keeping your resin in a heated space and only bringing it into the cooler work space just before using it. Another trick is to place the container in a tub of warm water. That will create a more even temperature environment for the resin as opposed to putting it on a heater, directly.
Barry Snyder uses a temperature controlled reptile heating pad to warm his resin.
Before mixing, I used a ceramic tile over my old muscle heating pad in a cardboard (beer case) box to warm up some epoxy resin and hardener yesterday . Warming both first makes them more fluid for thorough mixing. I have to keep an eye on my heating pad with a thermometer (heating pad can get resin temps up to 94 F).
A water bath would be a good way to moderate heating. Would give more uniform heating but slower. (Be careful not to short out an electrical heating source underneath it though).
Cool/cold air in your glassing room will slow the curing process and can cause problems. I like air temps no less than 68 F but prefer 75 F.
Made this low budget resin warmer several years ago. Still using it. May upgrade it with a reptile heating pad/mat for better temp control.
